SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

Current report pursuant to the

Section 13 or 15(d) of the

Securities and Exchange Act of 1934

April 21, 2003

Date of Report (Date of earliest event reported)

ENTERPRISE FINANCIAL SERVICES CORP

(Exact Name of Registrant as Specified in its Charter)

(314) 725-5500

(Registrant’s Telephone Number)

ITEM 7. Financial Statements and Exhibits

(c) Exhibits

The following exhibit is furnished pursuant to Item 12 (reported herein under the Item 9 caption in accordance with the guidance provided in SEC Release Nos. 33-8216; 34-475831, is not to be considered “filed” under the Securities Exchange Act of 1934, as amended (“Exchange Act”), and shall not be incorporated by reference into any of Enterprise Financial Services Corp’s (“Registrant”) previous or future filings under the Securities Act of 1933, as amended, or the Exchange Act.

ITEM 9. INFORMATION FURNISHED UNDER ITEM 12 RESULTS OF OPERATIONS AND FINANCIAL CONDITION

On April 21, 2003, Registrant issued an earnings release related to its quarterly period ended March 31, 2003 and the text of that release, as required by Item 12 of Form 8-K, is attached hereto as Exhibit 99.1.

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the Registrant has duly caused this report to be signed on its behalf by the undersigned, thereto duly authorized.

Date: April 22, 2003

INDEX TO EXHIBITS