Exhibit 99.1

For more information, contact:

Kevin Eichner (314) 725 5500

Frank Sanfilippo (314) 725 5500

Katie Hollar (816) 221 7500

ENTERPRISE FINANCIAL REPORTS 34.5% INCREASE IN EARNINGS OVER

PREVIOUS YEAR

Trust Income Grows 43.5%

St. Louis, April 20, 2004 – Enterprise Financial Services Corp (OTCBB: EFSC), the parent company of Enterprise Bank and Trust reported net income of $1.5 million or $0.15 per fully diluted share for the three months ended March 31, 2004. For the three months ended March 31, 2003, net income was $1.1 million or $0.12 per fully diluted share. The reported earnings represent a 34.5% increase over the same quarter in 2003.

Portfolio loans grew by $119 million or 16.7% since March 31, 2003 and ended the quarter at $831 million. This growth was funded by a $120 million increase in deposits or 16.3% for the same period. Net interest income for the first quarter of 2004 was $8.4 million, a $336,000 or 4.2% increase over the same period last year. The net interest rate margin for the first quarter of 2004 was 3.88% compared to 4.08% in the same period last year.

“We are very pleased with our continued momentum,” said Kevin Eichner, president and CEO of Enterprise Financial. “Our growth is strong relative to our peers, and reflects the impact our talent is having in the marketplace. When we are able to grow at these rates while holding our non-interest expense at less than a 2% growth rate, it obviously bodes well for core earnings.”

In addition to its outstanding growth in its commercial banking business, the Company’s Wealth Management segment also enjoyed a very positive quarter. Trust income grew by $257,000 or 43.5% for the first three months of 2004 versus 2003. Assets under administration in Enterprise Trust were $1.17 billion at March 31, 2004 versus $986 million at March 31, 2003, an 18.2% increase. The Company also launched its Business Consulting and Wealth Products units in the first quarter to further enhance its Wealth Management offerings to its clients.

The provision for loan losses was $597,000 for the first quarter of 2004 compared to $999,000 for the same period in 2003. The allowance for loan losses of $10.69 million at March 31, 2004 represents 1.29% of outstanding portfolio loans, unchanged from March 31, 2003.

Enterprise Financial operates commercial banking and wealth management businesses in metropolitan St. Louis and Kansas City, with a primary focus on serving the needs of privately held businesses, their owners and other success-minded individuals.

Please refer to Enterprise Financial’s consolidated balance sheets as of March 31, 2004 and 2003 and consolidated statements of operations for the three months ended March 31, 2004 and 2003 attached for more details.

###

Readers should note that in addition to the historical information contained herein, this press release may contain forward-looking statements which are inherently subject to risks and uncertainties that could cause actual results to differ materially from those contemplated from such statements. Factors that could cause or contribute to such differences include, but are not limited to, burdens imposed by federal and state regulations of banks, credit risk, exposure to local economic conditions, risks associated with rapid increase or decrease in prevailing interest rates and competition from banks and other financial institutions, as well as those in Enterprise Financial’s 2003 Annual Report on Form 10-K.

ENTERPRISE FINANCIAL SERVICES CORP AND SUBSIDIARIES

Consolidated Balance Sheets (unaudited)

March 31, 2004 and 2003

(Dollars in thousands, except share data)

	2004		2003
Assets
Cash and due from banks	$	25,417	$	42,440
Federal funds sold		41,750		30,828
Interest-bearing deposits		843		93
Investments in debt and equity securities:
Available for sale, at estimated fair value		51,404		69,829
Held to maturity, at amortized cost (estimated fair value of $9 at March 31, 2004 and $12 at March 31, 2003)		9		12
Total investments in debt and equity securities		51,413		69,841
Loans held for sale		2,645		3,868
Loans, less unearned loan fees		830,948		712,154
Less allowance for loan losses		10,686		9,175
Loans, net		820,262		702,979
Other real estate owned		653		450
Fixed assets, net		7,222		7,427
Accrued interest receivable		2,820		3,656
Goodwill		1,938		2,087
Assets held for sale		—		28,633
Prepaid expenses and other assets		8,631		10,459
Total assets	$	963,594	$	902,761
Liabilities and Shareholders’ Equity
Deposits:
Demand	$	171,176	$	165,465
Interest-bearing transaction accounts		58,179		54,286
Money market accounts		388,757		347,500
Savings		4,260		3,673
Certificates of deposit:
$100,000 and over		197,171		117,203
Other		41,098		52,053
Total deposits		860,641		740,180
Subordinated debentures		15,464		15,464
Federal Home Loan Bank advances		14,468		29,433
Notes payable and other borrowings		987		2,459
Accrued interest payable		1,021		1,269
Liabilities held for sale		—		48,862
Accounts payable and accrued expenses		3,857		4,941
Total liabilities		896,438		842,608
Shareholders’ equity:
Common stock, $.01 par value; authorized 20,000,000 shares; issued and outstanding 9,676,675 shares at March 31, 2004 and 9,538,416 shares at March 31, 2003		97		95
Surplus		40,233		38,867
Retained earnings		26,117		19,618
Accumulated other comprehensive income		709		1,573
Total shareholders’ equity		67,156		60,153
Total liabilities and shareholders’ equity	$	963,594	$	902,761

ENTERPRISE FINANCIAL SERVICES CORP AND SUBSIDIARIES

Consolidated Statements of Operations (unaudited)

Three Months Ended March 31, 2004 and 2003

(Dollars in thousands, except share data)

	2004		2003
Interest income:
Interest and fees on loans	$	10,457	$	10,369
Interest on debt and equity securities:
Taxable		409		467
Nontaxable		10		—
Interest on federal funds sold		48		38
Dividends on equity securities		20		24
Total interest income		10,944		10,898
Interest expense:
Interest-bearing transaction accounts		39		52
Money market accounts		859		927
Savings		3		14
Certificates of deposit:
$100,000 and over		861		668
Other		264		563
Subordinated debentures		317		318
Federal Home Loan Bank borrowings		185		290
Notes payable and other borrowings		26		11
Total interest expense		2,554		2,843
Net interest income		8,390		8,055
Provision for loan losses		597		999
Net interest income after provision for loan losses		7,793		7,056
Noninterest income:
Service charges on deposit accounts		457		487
Trust income		847		590
Other service charges and fee income		107		97
Gain on sale of mortgage loans		68		251
Gain on sale of securities		1		78
Total noninterest income		1,480		1,503
Noninterest expense:
Compensation		3,852		3,528
Payroll taxes and employee benefits		837		672
Occupancy		496		476
Furniture and equipment		182		221
Data processing		185		242
Other		1,320		1,619
Total noninterest expense		6,872		6,758
Income before income tax expense		2,401		1,801
Income tax expense		875		666
Net income	$	1,526	$	1,135
Per share amounts
Basic earnings per share	$	0.16	$	0.12
Basic weighted average common shares outstanding		9,640,145		9,520,631
Diluted earnings per share	$	0.15	$	0.12
Diluted weighted average common shares outstanding		9,942,143		9,825,620