FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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(Print or Type Responses)

1. Name and Address of Reporting Person * MUELLER JEROME M   2. Issuer Name and Ticker or Trading Symbol ENTERPRISE FINANCIAL SERVICES CORP [EFSC] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) SVP Marketing (Last) (First) (Middle) 150 N. MEREMAC 3. Date of Earliest Transaction (Month/Day/Year) 05/03/2012 (Street) ST. LOUIS, MO 63105 4. If Amendment, Date Original Filed(Month/Day/Year) 6. Individual or Joint/Group Filing(Check Applicable Line) _X_ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock               21,685 D

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction Code (Instr. 8)

5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5)

6. Date Exercisable and Expiration Date (Month/Day/Year)

7. Title and Amount of Underlying Securities (Instr. 3 and 4)

8. Price of Derivative Security (Instr. 5)

9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

Code

V

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Restricted Share Units

(1)

05/03/2012

A

4,761

(2)

(2)

Common Stock

5,016

$ 0

5,016

D

Stock Settled Stock Appreciation Rights

$ 25.63

12/15/2007(3)

06/15/2017

Common Stock

4,953

4,953

D

Stock Settled Stock Appreciation Rights

$ 20.63

12/15/2008(4)

06/13/2018

Common Stock

3,000

3,000

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
MUELLER JEROME M 150 N. MEREMAC ST. LOUIS, MO 63105			SVP Marketing

Signatures

/s/ Jerome M. Mueller		05/07/2012
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	The RSUs were granted pursuant to the Company's 2002 Stock Incentive Plan. Each RSU represents the right to receive one share of Common Stock, subject to adjustment as provided in the Grant Agreement.
(2)	The RSUs vest at a rate of 20% annually over five years, subject to continued employment of the reporting person. Vesting occurs on December 15 of each year, commencing in the calendar year of the grant. On each vesting date, for each RSU vesting on such date, the reporting person will receive one share of Common Stock.
(3)	Each SSAR consists of the right to receive an amount, in common stock, equal to the excess of the fair market value of a share of common stock on the date of exercise over the exercise price of the SSAR. The SSARs vest at a rate of 20% annually over five years, subject to continued employement of the reporting person. Vesting occurs on December 15 of each year, commencing December 15, 2007.
(4)	Each SSAR consists of the right to receive an amount, in common stock, equal to the excess of the fair market value of a share of common stock on the date of exercise over the exercise price of the SSAR. The SSARs vest at a rate of 20% annually over five years, subject to continued employment of the reporting person. Vesting occurs on December 15 of each year, commencing December 15, 2008.

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