SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                    FORM 11-K
                                  ANNUAL REPORT
                        PURSUANT TO SECTION 15(d) OF THE
                         SECURITIES EXCHANGE ACT OF 1934

[X]      ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT
OF 1934
         For the fiscal year ended December 31, 2002

                                       OR

[ ]      TRANSITION REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE
ACT OF 1934
         For the transition period from ___________ to _____________

Commission File Number: 1-3305
Employer Identification Number: 22-1109110
Plan Number: 001

              MERCK & CO., INC. EMPLOYEE SAVINGS AND SECURITY PLAN
--------------------------------------------------------------------------------
                            (Full title of the plan)

                                MERCK & CO., INC.
--------------------------------------------------------------------------------
          (Name of issuer of the securities held pursuant to the plan)

                                  P.O. Box 100
                    Whitehouse Station, New Jersey 08889-0100
--------------------------------------------------------------------------------
                     (Address of principal executive office)



MERCK & CO., INC.
EMPLOYEE SAVINGS AND SECURITY PLAN

EMPLOYER IDENTIFICATION NUMBER:  22-1109110
PLAN NUMBER:  001
INDEX



                                                                                                             PAGE
                                                                                                          
Report of Independent Accountants                                                                              1

Financial Statements:

   Statements of Net Assets Available for Benefits as of
     December 31, 2002 and 2001                                                                                2

   Statement of Changes in Net Assets Available for                                                            3
     Benefits for the Year Ended December 31, 2002

Notes to Financial Statements                                                                                4-9

Supplemental Schedule*:

   H - Line 4i - Schedule of Assets (Held at End of Year)                                                     10

Signature                                                                                                     11

Exhibit Index                                                                                                 12

Exhibit 23 - Consent of Independent Accountants                                                               13

Exhibit 99.1 - Certification by the Chief Executive Officer of the Merck & Co., Inc.
Employee Savings and Security Plan Pursuant to 18 U.S.C. Section 1350, as Adopted                             14
Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002

Exhibit 99.2 - Certification by the Chief Financial Officer of the Merck & Co., Inc.
Employee Savings and Security Plan Pursuant to 18 U.S.C. Section 1350, as Adopted                             15
Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002


*   Other schedules required by Section 2520.103-10 of the Department of Labor
    Rules and Regulations for Reporting and Disclosure under the Employee
    Retirement Income Security Act of 1974 are omitted because they are not
    applicable.


[PRICEWATERHOUSECOOPERS LOGO]                        PRICEWATERHOUSECOOPERS LLP
                                                     400 Campus Drive
                                                     P.O. Box 988
                                                     Florham Park NJ 07932
                                                     Telephone (973) 236-4000
                                                     Facsimile (973) 236-5000

                       REPORT OF INDEPENDENT ACCOUNTANTS

To the Participants in the Merck & Co., Inc.
Employee Savings and Security Plan and
Merck & Co., Inc.:

In our opinion, the accompanying statements of net assets available for benefits
and the related statement of changes in net assets available for benefits
present fairly, in all material respects, the net assets available for benefits
of the Merck & Co., Inc. Employee Savings and Security Plan (the "Plan") as of
December 31, 2002 and 2001 and the changes in net assets available for benefits
for the year ended December 31, 2002 in conformity with accounting principles
generally accepted in the United States of America. These financial statements
are the responsibility of the Plan's management; our responsibility is to
express an opinion on these financial statements based on our audits. We
conducted our audits of these statements in accordance with auditing standards
generally accepted in the United States of America, which require that we plan
and perform the audit to obtain reasonable assurance about whether the financial
statements are free of material misstatement. An audit includes examining, on a
test basis, evidence supporting the amounts and disclosures in the financial
statements, assessing the accounting principles used and significant estimates
made by management, and evaluating the overall financial statement presentation.
We believe that our audits provide a reasonable basis for our opinion.

Our audits were conducted for the purpose of forming an opinion on the basic
financial statements taken as a whole. The supplemental Schedule of Assets (Held
at End of Year) is presented for the purpose of additional analysis and is not a
required part of the basic financial statements but is supplementary information
required by the Department of Labor's Rules and Regulations for Reporting and
Disclosure under the Employee Retirement Income Security Act of 1974. This
supplemental schedule is the responsibility of the Plan's management. The
supplemental schedule has been subjected to the auditing procedures applied in
the audits of the basic financial statements and, in our opinion, is fairly
stated in all material respects in relation to the basic financial statements
taken as a whole.

/s/ PricewaterhouseCoopers LLP

June 20, 2003

                                      -1-


MERCK & CO., INC.
EMPLOYEE SAVINGS AND SECURITY PLAN

STATEMENTS OF NET ASSETS AVAILABLE FOR BENEFITS



                                                        DECEMBER 31,
                                                   2002             2001
                                                         
ASSETS
    Investment in the Master Trust            $2,479,000,771   $2,631,042,137
    Participant loans at contract value           36,825,429       37,605,117
                                              --------------   --------------

         Total investments                     2,515,826,200    2,668,647,254
                                              --------------   --------------

RECEIVABLES
    Employer's contribution                        5,797,892          132,484
    Participants' contributions                   13,422,754          282,035
                                              --------------   --------------

         Total receivables                        19,220,646          414,519
                                              --------------   --------------

Net assets available for benefits             $2,535,046,846   $2,669,061,773
                                              ==============   ==============


   The accompanying notes are an integral part of these financial statements.

                                      -2-


MERCK & CO., INC.
EMPLOYEE SAVINGS AND SECURITY PLAN

STATEMENT OF CHANGES IN NET ASSETS AVAILABLE FOR BENEFITS



                                                    YEAR ENDED
                                                   DECEMBER 31,
                                                       2002
                                               
 ADDITIONS TO NET ASSETS ATTRIBUTED TO
    Contributions to the Plan
         By participants                          $  182,592,732
         By employer                                  73,324,006
                                                  --------------

            Total contributions                      255,916,738

    Transfers in                                       1,418,797
                                                  --------------

            Total additions                          257,335,535
                                                  --------------

DEDUCTIONS FROM NET ASSETS ATTRIBUTED TO
    Investment loss from the Master Trust            236,421,113
    Benefits paid to participants                    148,873,763
    Transfers out                                      6,055,586
                                                  --------------

            Total deductions                         391,350,462
                                                  --------------

            Net decrease                             134,014,927

NET ASSETS AVAILABLE FOR BENEFITS
    Beginning of year                              2,669,061,773
                                                  --------------

    End of year                                   $2,535,046,846
                                                  ==============


   The accompanying notes are an integral part of these financial statements.

                                      -3-


MERCK & CO., INC.
EMPLOYEE SAVINGS AND SECURITY PLAN

NOTES TO FINANCIAL STATEMENTS

1.       DESCRIPTION OF PLAN

         The following description of the Merck & Co., Inc. Employee Savings and
         Security Plan (the "Plan") provides only general information.
         Participants should refer to the Plan document for a more complete
         description of the Plan's provisions.

         GENERAL

         The Plan was designed to provide an easy, economical way for employees
         to become stockholders of Merck & Co., Inc. (the "Company" or "Merck")
         as well as a systematic means of saving and investing for the future.
         Regular full-time, part-time, and temporary employees of the Company
         and of certain wholly-owned subsidiaries as defined by the Plan
         document who were not covered by a collective bargaining agreement are
         eligible to enroll in the Plan as of the first day of the third month
         following their date of hire.

         The Plan is administered by a management committee appointed by the
         Chief Executive Officer of the Company.

         The Plan is subject to the provisions of the Employee Retirement Income
         Security Act of 1974 ("ERISA").

         MASTER TRUST

         The assets of the Plan are maintained, for investment purposes only, on
         a commingled basis with the assets of the Merck & Co., Inc. Employee
         Stock Purchase & Savings Plan and the Merck-Medco Managed Care 401(k)
         Savings Plan in the Merck & Co., Inc. Employee Savings & Security Plan
         and the Merck & Co., Inc. Employee Stock Purchase & Savings Plan Trust
         (the "Master Trust"). The plans do not own specific Master Trust assets
         but rather maintain individual beneficial interests in such assets. The
         portion of fund assets allocable to each plan is based upon the
         participant's account balance within each plan. Investment income for
         each fund is allocated to each plan based on the relationship of each
         plan's beneficial interest in the fund to the total beneficial interest
         of all plans in the fund.

         CONTRIBUTIONS

         Participants may contribute from 2% up to 18% of their base pay.
         Employees earning less than $90,000 are allowed to contribute a maximum
         of 18% of base pay. Effective January 1, 2003, employees earning less
         than $90,000 are allowed to contribute a maximum of 25% of base pay.
         Employees earning $90,000 or more are limited to maximum contributions
         of 15% of base pay. In addition, the Company matches 75% of employee
         contributions up to 6% of base pay per pay period. Company matching
         contributions are invested according to the following age parameters:

         Under age 50 -- 50% of Company matching contributions is invested in
         the Merck Common Stock Fund (non-participant directed) and 50% is
         invested in the funds to which the participant is currently
         contributing (participant directed).

                                       -4-



MERCK & CO., INC.
EMPLOYEE SAVINGS AND SECURITY PLAN

NOTES TO FINANCIAL STATEMENTS

         Age 50 and above -- Participants have the option to invest all Company
         matching contributions in any of the available fund options
         (participant directed). Also, the Economic Growth and Tax Relief
         Reconciliation Act of 2001 permits catch-up contributions that are
         designed to provide individuals age 50 and above with an additional
         pre-tax retirement savings opportunity. As such, effective July 1,
         2002, eligible participants in the Plan may contribute an additional
         $1,000 for 2002. The limit for this "catch-up" contribution increases
         by $1,000 each year until it reaches $5,000 a year in 2006.

         Participants direct the investment of their contributions into any
         investment option available under the Plan, including Merck Common
         Stock (participant directed). During 2001, the Plan offered 21 mutual
         funds and the Merck Common Stock Fund. Effective January 1, 2002, the
         Plan offers 20 mutual funds and the Merck Common Stock Fund.

         PARTICIPANT ACCOUNTS

         Each participant's account is credited with the participant's
         contribution, the Company's matching contribution and allocation of
         Plan earnings. The allocation is based on participants' account
         balances, as defined in the Plan document.

         VESTING

         Participants are immediately vested in their contributions, all Company
         matching contributions, plus actual earnings thereon.

         PARTICIPANT LOANS

         Participants may borrow from their account balances with interest
         charged at the prime rate plus 1%. Loan terms range from one to five
         years or up to thirty years for the purchase of a primary residence.
         The minimum loan is $500 and the maximum loan is the lesser of $50,000
         less the highest outstanding loan balance during the one year period
         prior to the new loan application date, or 50% of the participant's
         account balance less any current outstanding loan balance.

         PAYMENT OF BENEFITS

         In-service (which include hardship withdrawals) and termination
         distributions are made throughout the year in accordance with
         applicable Plan provisions.

2.       SUMMARY OF ACCOUNTING POLICIES

         BASIS OF ACCOUNTING

         The accompanying financial statements are prepared on the accrual basis
         of accounting.

         USE OF ESTIMATES

         The financial statements are prepared in conformity with accounting
         principles generally accepted in the United States of America and,
         accordingly, include amounts that are based on management's best
         estimates and judgments. Actual results could differ from these
         estimates.

         INVESTMENT VALUATION AND INCOME RECOGNITION

         Valuation of investments of the Plan represents the Plan's allocable
         portion of the Master Trust. Participant loans are valued at cost which
         approximates fair value.

                                       -5-



MERCK & CO., INC.
EMPLOYEE SAVINGS AND SECURITY PLAN

NOTES TO FINANCIAL STATEMENTS

         Purchases and sales of securities are recorded on a trade-date basis.
         Dividend income is recorded on the ex-dividend date. The net
         appreciation (depreciation) in market value of investments is based on
         the beginning of the year market value or value at the time of purchase
         during the year and is included in the statement of changes in net
         assets available for benefits.

         CONTRIBUTIONS

         Employee and Company matching contributions are recorded in the period
         in which the Company makes the payroll deductions from the participant
         earnings.

         PAYMENT OF BENEFITS

         Benefits are recorded when paid.

         EXPENSES

         The Plan's administrative expenses are paid by the Company.

         RISKS AND UNCERTAINTIES

         The Plan provides for various investment options in investment
         securities. Investment securities, in general, are exposed to various
         risks, such as interest rate, credit and overall market volatility. Due
         to the level of risk associated with certain investment securities, it
         is reasonably possible that changes in the values of investment
         securities will occur in the near term and that such changes could
         materially affect the amounts reported in the statements of net assets
         available for benefits.

3.       NON-PARTICIPANT-DIRECTED INVESTMENTS

         The non-participant-directed portion of the Company match is invested
         in the Merck Common Stock Fund. Information about the net assets and
         the significant components of the changes in net assets relating to the
         Merck Common Stock Fund is as follows:



                                                          DECEMBER 31,
                                                     2002              2001
                                                            
Net assets
 Investment in Master Trust                     $1,275,213,183    $1,323,494,916
                                                --------------    --------------



                                       -6-



MERCK & CO., INC.
EMPLOYEE SAVINGS AND SECURITY PLAN

NOTES TO FINANCIAL STATEMENTS





                                                  YEAR ENDED
                                                 DECEMBER 31,
                                                     2002
                                             
Additions to net assets
 Contributions                                  $   91,148,417
 Transfers in                                       64,067,128
 Loan repayments                                     6,673,308
                                                --------------

  Total additions                                  161,888,853
                                                --------------

Deductions from net assets
 Investment loss                                   (16,475,580)
 Benefits paid                                     (55,985,787)
 Transfer out                                     (131,622,855)
 Loan issuance                                      (6,086,364)
                                                --------------

  Total deductions                                (210,170,586)
                                                --------------

   Net decrease                                 $  (48,281,733)
                                                ==============


4.       RELATED-PARTY TRANSACTIONS

         Certain Plan investments are shares of mutual funds managed by Fidelity
         Management Trust Company ("Fidelity"). Fidelity is the trustee as
         defined by the Plan and, therefore, these transactions qualify as
         party-in-interest transactions.

         Merck & Co., Inc. also is a party-in-interest to the Plan under the
         definition provided in Section 3(14) of ERISA. Therefore, Merck Common
         Stock Fund transactions qualify as party-in-interest transactions.

5.       PLAN TERMINATION

         Although it has not expressed any intent to do so, the Company has the
         right under the Plan to discontinue its contributions at any time and
         to terminate the Plan subject to the provisions of ERISA.

6.       TAX STATUS

         The Plan obtained a tax determination letter from the Internal Revenue
         Service dated September 18, 1995 indicating that it had been designed
         in accordance with applicable sections of the Internal Revenue Code
         ("IRC"). However, the Plan has been amended since the receipt of the
         determination letter. The Plan sponsor and legal counsel believe that
         the Plan is designed and currently operated in compliance with the IRC.
         Therefore, no provision for income taxes has been made.

                                       -7-



MERCK & CO., INC.
EMPLOYEE SAVINGS AND SECURITY PLAN

NOTES TO FINANCIAL STATEMENTS

7.       OTHER MATTERS

         Transfers during 2002 consist of transfers of $1,396,580 between the
         Plan and the Merck & Co., Inc. Employee Stock Purchase and Savings Plan
         for employees who changed their status during the year, $16,517 for
         employees who transferred in from the Merck-Medco Managed Care 401(k)
         Savings Plan during the year, and $5,700 for employees who transferred
         in from the Merck Puerto Rico Employee Savings and Security Plan.

         Transfers out consist of transfers of $171,828 for employees who
         transferred out to the Merck & Co., Inc. Employee Stock Purchase and
         Savings Plan, $5,855,258 for employees who transferred out to the
         Merck-Medco Managed Care 401(k) Savings Plan, and $28,500 for employees
         who transferred out to the Merck Puerto Rico Employee Savings and
         Security Plan.

8.       MASTER TRUST

         The Plan has a 79% and 81% interest in the Master Trust at December 31,
         2002 and December 31, 2001, respectively. The net assets of the Master
         Trust are as follows:



                                                                   DECEMBER 31,
                                                              2002              2001
                                                                     
         Mutual Funds                                    $1,472,422,521    $1,546,205,918
         Merck Common Stock                               1,651,008,624     1,713,814,350
         Accrued interest and dividends                      10,375,281        10,068,775
                                                         --------------    --------------
                                                         $3,133,806,426    $3,270,089,043
                                                         ==============    ==============




                                       -8-



MERCK & CO., INC.
EMPLOYEE SAVINGS AND SECURITY PLAN

NOTES TO FINANCIAL STATEMENTS

Changes in net assets for the year ended  December 31, 2002 for the Master Trust
are as follows:


                                             
Additions to net assets
 Contributions
  Participant                                   $  235,188,546
  Employer                                          93,535,066
                                                --------------

   Total contributions                             328,723,612
                                                --------------

 Transfers in                                        8,487,705
 Loan repayments                                    21,359,843
                                                --------------

   Total additions                                 358,571,160
                                                --------------

Deductions from net assets
 Investment loss, net
  Interest and dividends                            64,130,614
  Net depreciation in mutual funds                (285,057,632)
  Net depreciation in Merck Common Stock           (59,679,186)
                                                --------------

   Total investment loss                          (280,606,204)
                                                --------------

 Benefits paid                                    (180,707,030)
 Transfers out                                      (8,482,149)
 Loan issuance                                     (25,058,394)
                                                --------------

   Total deductions                               (494,853,777)
                                                --------------

   Net decrease                                   (136,282,617)
                                                --------------

Net assets
 Beginning of year                               3,270,089,043
                                                --------------

 End of year                                    $3,133,806,426
                                                ==============


                                       -9-



MERCK & CO., INC.
EMPLOYEE SAVINGS AND SECURITY PLAN

                                                                      SCHEDULE H
LINE 4i - SCHEDULE OF ASSETS (HELD AT END OF YEAR)               EIN: 22-1109110
DECEMBER 31, 2002                                                  PLAN NO.: 001



                                                    (c) DESCRIPTION OF INVESTMENT INCLUDING
            (b) IDENTITY OF ISSUE, BORROWER,    MATURITY DATE, RATE OF INTEREST, COLLATERAL, PAR               (e) CURRENT
(a)              LESSOR OR SIMILAR PARTY                        OR MATURITY VALUE                  (d) COST        VALUE
                                                                                                  
*           Participants' Loans                 Interest rates ranging from 6% to 12.5% and with
                                                maturities through 2032                                   -   $  36,825,429
                                                                                                              -------------
                                                Total                                                         $  36,825,429
                                                                                                              =============


*        Denotes a party-in-interest to the Plan.

                                      -10-



                                    SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the
undersigned plan administrator has duly caused this annual report to be signed
on behalf of the Merck & Co., Inc. Employee Savings and Security Plan by the
undersigned hereunto duly authorized.

                                        Merck & Co., Inc., as plan administrator

                                        By: /s/ Caroline Dorsa
                                            ------------------------------------
                                            Caroline Dorsa
                                            Vice President & Treasurer

June 27, 2003

                                      -11-



                                  EXHIBIT INDEX



Exhibit
Number       Document                                                           Page
-------      --------                                                           ----
                                                                          
23           Consent of Independent Accountants                                  13

99.1         Certification by the Chief Executive Officer of the Merck & Co.,
             Inc. Employee Savings and Security Plan Pursuant to 18 U.S.C.
             Section 1350, as Adopted Pursuant to Section 906 of the
             Sarbanes-Oxley Act of 2002                                          14

99.2         Certification by the Chief Financial Officer of the Merck & Co.,
             Inc. Employee Savings and Security Plan Pursuant to 18 U.S.C.
             Section 1350, as Adopted Pursuant to Section 906 of the
             Sarbanes-Oxley Act of 2002                                          15


                                      -12-