For more information contact:

Jerry Mueller, Senior Vice President (314) 512-7251

Ann Marie Mayuga, AMM Communications (314) 485-9499

ENTERPRISE FINANCIAL REPORTS 2011 FOURTH QUARTER

AND YEAR END RESULTS

• 2011 earnings increase to $25.4 million, or $1.34 per share, compared to $5.6 million, or $0.21 per share for 2010

• Fourth quarter earnings rose 45% from a year ago to $7.2 million

• Commercial and Industrial loans grew 8% over linked quarter and 29% over prior year period

• Nonperforming assets decrease 19% from one year ago to 1.74% of total assets

• Earnings conference call scheduled for Thursday, May 3, 2012

St. Louis, April 23, 2012. Enterprise Financial Services Corp (NASDAQ: EFSC) (the “Company”) reported net income of $25.4 million for the year ended December 31, 2011, compared to net income of $5.6 million for the prior year period. After deducting dividends on preferred stock, the Company reported net income of $1.34 per diluted share for 2011, compared to net income of $0.21 per diluted share for 2010.

For the fourth quarter of 2011, the Company reported net income of $7.2 million, an increase of 45% compared to net income of $5.0 million for the prior year period. After deducting dividends on preferred stock, the Company reported net income of $0.36 per diluted share for the fourth quarter of 2011, compared to $0.29 for the fourth quarter of 2010. The 2011 results reflect the additional shares issued with the Company's $35 million public common stock offering in May 2011.

Peter Benoist, President and CEO, commented, "The sharp increase in net earnings was primarily attributable to strong improvements in several areas of our core banking business during the quarter and for the year. Organic loans increased 2% in the quarter and 7% for the full year. Commercial and industrial loans showed particular strength, increasing 29% year over year, as we continue to gain market share."

Benoist continued, "Our acquisition of First National Bank of Olathe added $423 million in core deposits and contributed significantly to the Company's 24% overall increase in core deposits for the year. Net interest income increased 34% over the prior year as a result of a growing organic loan book, coupled with a declining cost of funds and robust yields on our acquired loss share loan portfolios. Additionally, the Company showed marked improvement in asset quality while continuing to maintain strong loan loss reserves and nonperforming loan coverage ratios."

Restatement of Financial Statements

On January 25, 2012, the Company disclosed that it had discovered an error in its process to record income on loans covered by FDIC loss share agreements. These acquired loans are initially recorded at fair value (as determined by the present value of expected future cash flows) with no valuation allowance. The difference between the undiscounted cash flows expected at acquisition and the investment in the loans, or the "accretable yield", is recognized as interest income on a level-yield method over the life of the loans. In accounting for income from the acquired loans, the Company recorded both the accretable yield and contractually required interest payments. The

1

Company should not have recognized the contractually required interest payments. As a result, both interest income and the carrying value of the acquired loans were overstated. This affected income reported on the loans acquired in FDIC assisted transactions since December 2009.

In addition to the adjustments relating to the acquired loan contractual interest described above, the Company has corrected other errors that had been previously identified but not corrected because they were not material, individually or in the aggregate, to the consolidated financial results. These items included changes in accrual estimates and financial statement reclassifications. The information in this release and accompanying tables reflect the impact of the restatement.

Reduction in Goodwill Associated with First National Bank of Olathe (FNBO) Acquisition

In conjunction with the August 12, 2011 acquisition of FNBO and as reported in the Form 8-K/A filed on October 28, 2011, the Company initially recorded $43.9 million in goodwill. The fair value estimates underlying the goodwill were provisional and are subject to change for up to one year after the closing date of the acquisition. Based on additional information regarding fair values, primarily related to other real estate, certain other assets and the FDIC clawback liability, the Company refined the fair values which reduced the amount of goodwill associated with the FNBO acquisition by $17.2 million to $26.7 million. The goodwill adjustment includes the $12.5 million reduction to the FNBO purchase price as reported in the Form 8-K filed on March 22, 2012. The reduction in goodwill had no effect on earnings. At December 31, 2011, total goodwill on the Company's balance sheet was $30.3 million.

Banking Segment

Deposits

Total deposits at December 31, 2011 were $2.8 billion, a decrease of $25.9 million, or 1%, from September 30, 2011 and $493.6 million, or 21%, higher than December 31, 2010. The year over year increase in deposits was largely comprised of noninterest-bearing demand deposits and money market and savings accounts with higher cost certificates of deposit declining during the year. Certificates of deposit fell $84.0 million, or 9%, during the fourth quarter and declined $44.3 million, or 5%, since year end 2010, consistent with the Company's intention to reduce its cost of funds. Money market, savings accounts and other interest-bearing transaction accounts increased $29.9 million, or 2%, over the linked quarter and $318.6 million, or 30%, over the prior year period, primarily as a result of the FNBO acquisition.

Noninterest-bearing demand deposits rose $28.2 million, or 5%, in the linked quarter and $219.4 million, or 60%, from the prior year period. Noninterest-bearing demand deposits increased to 21% of total deposits at December 31, 2011, compared to 20% at September 30, 2011 and 16% at December 31, 2010. While strong marketing and sales activity and the FNBO acquisition accounted for a significant portion of the increase, demand deposit balances have been elevated throughout the year due to the relative indifference between demand deposit earnings credit rates and the low interest rates paid on interest-bearing account alternatives.

The FNBO acquisition added $423.1 million in deposits in the third quarter of 2011. These deposits included $66.9 million in noninterest-bearing demand deposits, $123.6 million in money market and other interest-bearing transaction accounts, and $232.6 million in certificates of deposit.

Core deposits, which exclude brokered certificates of deposit and include reciprocal CDARS deposits represented 95% of total deposits at December 31, 2011, compared to 96% in the linked quarter and 93% in the prior year period.

Loans

Portfolio loans totaled $2.2 billion at December 31, 2011, including $300.6 million of loans covered under FDIC loss share ("Covered loans"). Excluding Covered loans, portfolio loans increased $29.1 million, or 2%, in the fourth quarter of 2011 and $130.7 million, or 7%, for the year.

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Commercial and industrial loan growth has been particularly strong and has increased for six consecutive quarters. Excluding the loans covered under loss share, Commercial and Industrial loans increased $57.1 million, or 8%, during the quarter and $169.3 million, or 29%, for the year and represent one-third of the Company's loan portfolio. Approximately 50% of the growth in Commercial and Industrial loan outstandings is attributable to new relationships originated during the year.

Asset quality

Nonperforming loans, including troubled debt restructurings of $10.0 million, were $41.6 million at December 31, 2011, compared to $48.0 million at September 30, 2011 and $46.4 million at December 31, 2010. During the quarter ended December 31, 2011, there were $11.1 million of additions to nonperforming loans, $5.6 million of charge-offs, $7.5 million of other principal reductions, $1.2 million of transfers to other real estate, and $3.9 million of transfers back to performing status. Nonperforming loans also include $0.8 million of accruing loans that are 90 days past due.

Nonperforming loans declined to 1.89% of total loans at December 31, 2011 versus 2.19% of total loans at September 30, 2011 and 2.46% at December 31, 2010.

Nonperforming loans by portfolio class at December 31, 2011 were as follows:

(in millions)	Total portfolio				Nonperforming				% NPL
Construction, Real Estate/Land    Acquisition & Development	$	140.1			$	14.8			10.56	%
Commercial Real Estate - Investor Owned	477.2				11.1				2.33	%
Commercial Real Estate - Owner Occupied	334.4				4.6				1.38	%
Residential Real Estate	171.0				5.5				3.22	%
Commercial & Industrial	763.2				5.6				0.73	%
Consumer & Other	11.5				—				—
Portfolio loans covered under FDIC loss share	300.6				—				—
Total	$	2,198.0			$	41.6			1.89	%

Excluding non-accrual loans and Covered loans, portfolio loans that were 30-89 days delinquent at December 31, 2011 represented 0.31% of the total portfolio compared to 0.02% at September 30, 2011 and 0.13% of December 31, 2010.

Other real estate at December 31, 2011 was $53.7 million, compared to $72.6 million at September 30, 2011 and $36.2 million at December 31, 2010. The increase in other real estate in the third quarter was primarily attributable to the FNBO acquisition. Approximately 68% of total other real estate at December 31, 2011, or $36.5 million, was covered by an FDIC loss share agreement.

Other real estate not covered by an FDIC loss share agreement totaled $17.2 million at December 31, 2011, a decrease of $4.2 million from September 30, 2011. At December 31, 2010 other real estate not covered by a FDIC loss share agreement totaled $25.4 million.

During the fourth quarter of 2011, the Company sold $19.3 million of other real estate, recording a loss of $177,000. For the full year of 2011, the Company sold $44.6 million of other real estate at a net gain of $862,000.

Excluding other real estate covered under FDIC loss share, nonperforming assets as a percentage of total assets declined to 1.74% at December 31, 2011 from 2.07% at September 30, 2011 and 2.59% at December 31, 2010.

Net charge-offs in the fourth quarter of 2011 were $5.7 million, representing an annual rate of 1.03% of average loans, compared to net charge-offs of $4.8 million, an annualized rate of 0.90% of average loans, in the linked third

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quarter and $7.6 million, an annualized rate of 1.57% of average loans, in the fourth quarter of 2010. For 2011, net charge-offs were $19.2 million, or 0.94% of average loans.

There was no additional provision for loan losses for loans not covered under FDIC loss share in the fourth quarter of 2011, compared to $5.4 million in the third quarter of 2011 and $3.3 million in the fourth quarter of 2010. The Company did not record a loan loss provision in the fourth quarter of 2011 due to the absence of loan risk rating downgrades in the quarter. For Covered loans, the Company re-measures contractual and expected cashflows on a quarterly basis. When the re-measurement process results in a decrease in expected cash flows due to an increase in expected credit losses, impairment is recorded. As a result of this impairment, the FDIC loss share receivable is increased to reflect anticipated future cash to be received from the FDIC. The amount of the increase is determined based on the specific loss share agreement, but is generally 80% of the losses. In the third quarter of 2011, an impairment of $2.7 million was recorded for certain loan pools covered under loss share which was partially offset through noninterest income by an increase in the FDIC loss share receivable. In the fourth quarter of 2011, this impairment reversed, but was offset by impairment on other loan pools covered under loss share. The FDIC loss share receivable was adjusted accordingly.

The Company's allowance for loan losses was 1.80% of total loans at December 31, 2011, representing 95% of nonperforming loans. The loan loss allowance was 2.07% at September 30, 2011 representing 95% of nonperforming loans and 2.26% at December 31, 2010 representing 92% of nonperforming loans.

Net Interest Income

Net interest income for the banking segment in the fourth quarter rose 19% compared to the third quarter. On a year over year basis, net interest income increased $28 million, or 31%. Including the effect of parent company debt, the net interest rate margin was 4.35% for the fourth quarter of 2011, compared to 3.79% for the third quarter of 2011 and 4.09% for the fourth quarter of 2010. In the fourth quarter of 2011, the loans covered under FDIC loss share yielded 14.62%, including effects of accelerated discount accretion due to cash flows on paid off covered loans.

Absent Covered loans, related nonearning assets and acquired deposits, the net interest rate margin was 3.36% for the fourth quarter of 2011 compared to 3.38% for the third quarter of 2011. For 2011, the net interest rate margin, less the Covered loans, related nonearning assets and acquired deposits, was 3.42% compared to 3.53% for 2010.

Wealth Management Segment

Fee income attributable to the Wealth Management segment includes Wealth Management revenue and income from state tax credit brokerage activities. Fourth quarter Wealth Management revenues of $1.7 million were $164,000 and $99,000 lower than the linked quarter and prior year periods, respectively. For the year ended December 31, 2011, Wealth Management revenue was $6.8 million, an increase of $427,000 compared to the year ended December 31, 2010. Trust assets under administration were $1.6 billion at December 31, 2011, compared to $1.4 billion at September 30, 2011 and $1.5 billion at December 31, 2010.

State tax credit brokerage income, net of fair value marks on tax credit assets and related interest rate hedges, was $1.1 million for the fourth quarter of 2011, compared to $1.4 million for the third quarter of 2011 and near break even in the fourth quarter of 2010. Particularly strong sales results in this area during the second half of the year contributed to this improvement.

Capital

Total capital to risk-weighted assets was 13.78% at December 31, 2011 compared to 13.70% at September 30, 2011 and 14.11% at December 31, 2010. The tangible common equity ratio was 4.99% at December 31, 2011 versus 4.88% at September 30, 2011 and 5.15% at December 31, 2010. The lower tangible common equity ratio at December 31, 2011 was attributable to the Company's August 2011 acquisition of FNBO. The Company's Tier 1 common equity ratio was 7.32% at December 31, 2011 compared to 7.16% at September 30, 2011 and 7.16% at December 31, 2010. The Company believes that the tangible common equity and the Tier 1 common equity ratios are important financial measures of capital strength even though they are considered to be non-GAAP measures and

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are not part of the regulatory capital requirements to which the Company is subject. The attached tables contain a reconciliation of these ratios to U.S. GAAP.

Other Business Results

Noninterest expenses were $23.4 million for the quarter ended December 31, 2011, compared to $18.3 million for the quarter ended September 30, 2011 and $18.2 million for the quarter ended December 31, 2010. For the year, noninterest expenses were $77.7 million, an increase of $15.5 million, or 25%. Salaries and benefits increased $8.5 million, or 30%, year over year. The increase over the prior year period was primarily due to increases in salaries and benefits, occupancy, data processing and other operating expenses related to the 2011 acquisitions.

The Company's efficiency ratio was 71.4% for the quarter ended December 31, 2011 compared to 51.6% for quarter ended September 30, 2011 and 64.6% for the prior year period. The higher efficiency ratio for the fourth quarter was attributable to negative noninterest income due to the decline in the FDIC loss share receivable coupled with higher noninterest expenses. For 2011, the Company's efficiency ratio was 59.2% compared to 60.8% for 2010.

The Company will host a conference call at 1:00 p.m. CDT on Thursday, May 3, 2012. During the call, management will address both the 2011 results and the first quarter of 2012 results, which are expected to be released that morning. The call will be accessible on Enterprise Financial Services Corp's home page, at www.enterprisebank.com under “Investor Relations” and by telephone at 1-888-285-8004 (Conference ID #72468603.) Recorded replays of the conference call will be available on the website beginning two hours after the call's completion. The replay will be available for approximately two weeks following the conference call.

Enterprise Financial Services Corp operates commercial banking and wealth management businesses in metropolitan St. Louis, Kansas City, and Phoenix. The Company is primarily focused on serving the needs of privately held businesses, their owner families, executives and professionals.

# # #

Readers should note that in addition to the historical information contained herein, this press release contains 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. We use the words “expect” and “intend” and variations of such words and similar expressions in this communication to identify such forward-looking 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, changes in the appraised valuation of real estate securing impaired loans, outcomes of litigation and other contingencies, exposure to local and national economic conditions, risks associated with rapid increase or decrease in prevailing interest rates, effects of mergers and acquisitions, effects of critical accounting policies and judgments, legal and regulatory developments and competition from banks and other financial institutions, as well as other risk factors described in the Company's 2010 Annual Report on Form 10-K and in its Quarterly Reports on Form 10-Q filed subsequent thereto. Forward-looking statements speak only as of the date they are made, and the Company undertakes no obligation to update them in light of new information or future events unless required under the federal securities laws.

5

ENTERPRISE FINANCIAL SERVICES CORP

CONSOLIDATED FINANCIAL SUMMARY (unaudited)

	For the Quarter ended								For the Twelve Months ended
					Restated								Restated
(in thousands, except per share data)	Dec 31, 2011				Dec 31, 2010				Dec 31, 2011				Dec 31, 2010
INCOME STATEMENTS
NET INTEREST INCOME
Total interest income	$	39,463			$	32,271			$	142,840			$	116,394
Total interest expense	7,259				7,909				30,155				32,411
Net interest income	32,204				24,362				112,685				83,983
Provision for loan losses not covered under FDIC loss share	—				3,325				13,300				33,735
Provision for loan losses covered under FDIC loss share	(144		)		—				2,803				—
Net interest income after provision for loan losses	32,348				21,037				96,582				50,248
NONINTEREST INCOME
Wealth Management revenue	1,668				1,767				6,841				6,414
Deposit service charges	1,428				1,145				5,091				4,739
(Loss) gain on sale of other real estate	(177		)		(355		)		862				79
State tax credit activity, net	1,135				(3		)		3,645				2,250
Gain on sale of investment securities	2				781				1,450				1,987
Change in FDIC loss share receivable	(4,642		)		(336		)		(3,494		)		99
Other income	1,187				882				4,113				2,792
Total noninterest income	601				3,881				18,508				18,360
NONINTEREST EXPENSE
Employee compensation and benefits	10,557				7,320				36,839				28,316
Occupancy	1,415				1,126				5,001				4,297
Furniture and equipment	385				357				1,601				1,393
Other	11,070				9,428				34,277				28,206
Total noninterest expenses	23,427				18,231				77,718				62,212
Income from continuing operations before income tax expense	9,522				6,687				37,372				6,396
Income tax expense	2,316				1,701				11,949				823
Income from continuing operations	7,206				4,986				25,423				5,573
Dividends on preferred stock	(636		)		(622		)		(2,524		)		(2,467		)
Net income available to common shareholders	$	6,570			$	4,364			$	22,899			$	3,106
Basic earnings per share	$	0.37			$	0.29			$	1.37			$	0.21
Diluted earnings per share	$	0.36			$	0.29			$	1.34			$	0.21
Return on average assets	0.77		%		0.66		%		0.74		%		0.13		%
Return on average common equity	12.81		%		11.47		%		12.67		%		2.12		%
Efficiency ratio	71.41		%		64.55		%		59.24		%		60.79		%
Noninterest expenses to average assets	2.74		%		2.74		%		2.51		%		2.54		%
YIELDS (fully tax equivalent)
Loans not covered under FDIC loss share	5.31		%		5.45		%		5.39		%		5.52		%
Loans covered under FDIC loss share	14.62		%		18.74		%		14.17		%		15.35		%
Total portfolio loans	6.65		%		6.32		%		6.38		%		5.90		%
Securities	2.10		%		2.60		%		2.54		%		2.74		%
Federal funds sold	0.24		%		0.26		%		0.26		%		0.30		%
Yield on interest-earning assets	5.32		%		5.40		%		5.21		%		5.19		%
Interest-bearing deposits	0.90		%		1.21		%		1.04		%		1.36		%
Subordinated debt	5.32		%		5.71		%		5.31		%		5.82		%
Borrowed funds	1.84		%		2.32		%		1.91		%		2.46		%
Cost of paying liabilities	1.12		%		1.49		%		1.27		%		1.66		%
Net interest spread	4.20		%		3.91		%		3.94		%		3.53		%
Net interest rate margin	4.35		%		4.09		%		4.12		%		3.76		%

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ENTERPRISE FINANCIAL SERVICES CORP

CONSOLIDATED FINANCIAL SUMMARY (unaudited) (continued)

	At the Quarter ended
					Restated				Restated				Restated				Restated
(in thousands, except per share data)	Dec 31, 2011				Sep 30, 2011				Jun 30, 2011				Mar 31, 2011				Dec 31, 2010
BALANCE SHEETS
ASSETS
Cash and due from banks	$	20,791			$	26,015			$	22,806			$	18,542			$	23,413
Federal funds sold	143				2,371				1,321				1,464				3,153
Interest-bearing deposits	168,711				240,488				175,676				187,556				268,853
Debt and equity investments	607,709				477,131				486,990				496,419				373,824
Loans held for sale	6,494				5,076				1,688				3,142				5,640
Portfolio loans not covered under FDIC loss share	1,897,074				1,867,956				1,826,228				1,761,034				1,766,351
Portfolio loans covered under FDIC loss share	300,610				326,942				169,113				182,277				121,570
Total portfolio loans	2,197,684				2,194,898				1,995,341				1,943,311				1,887,921
Less allowance for loan losses	39,624				45,451				42,157				42,822				42,759
Net loans	2,158,060				2,149,447				1,953,184				1,900,489				1,845,162
Other real estate not covered under FDIC loss share	17,217				21,370				20,978				28,443				25,373
Other real estate covered under FDIC loss share	36,471				51,193				21,812				22,862				10,835
Premises and equipment, net	18,986				18,976				19,488				20,035				20,499
State tax credits, held for sale	50,446				56,278				57,058				59,928				61,148
FDIC loss share receivable	184,554				194,216				91,859				103,285				87,792
Goodwill	30,334				30,334				3,622				3,622				2,064
Core deposit intangible	9,285				9,471				1,791				1,921				1,223
Other assets	68,578				66,418				65,110				67,937				71,220
Total assets	$	3,377,779			$	3,348,784			$	2,923,383			$	2,915,645			$	2,800,199
LIABILITIES AND SHAREHOLDERS' EQUITY
Noninterest-bearing deposits	$	585,479			$	557,290			$	473,688			$	448,012			$	366,086
Interest-bearing deposits	2,205,874				2,259,972				1,937,589				1,982,418				1,931,635
Total deposits	2,791,353				2,817,262				2,411,277				2,430,430				2,297,721
Subordinated debentures	85,081				85,081				85,081				85,081				85,081
FHLB advances	102,000				102,000				102,000				107,300				107,300
Federal funds purchased	—				—				—				—				—
Other borrowings	154,545				100,729				87,774				97,898				119,333
Other liabilities	5,235				9,241				8,390				10,435				10,963
Total liabilities	3,138,214				3,114,313				2,694,522				2,731,144				2,620,398
Shareholders' equity	239,565				234,471				228,861				184,501				179,801
Total liabilities and shareholders' equity	$	3,377,779			$	3,348,784			$	2,923,383			$	2,915,645			$	2,800,199

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ENTERPRISE FINANCIAL SERVICES CORP

CONSOLIDATED FINANCIAL SUMMARY (unaudited) (continued)

	For the Quarter ended
					Restated				Restated				Restated				Restated
(in thousands, except per share data)	Dec 31, 2011				Sep 30, 2011				Jun 30, 2011				Mar 31, 2011				Dec 31, 2010
EARNINGS SUMMARY
Net interest income	$	32,204			$	26,769			$	31,004			$	22,708			$	24,362
Provision for loan losses not covered under FDIC loss share	—				5,400				4,300				3,600				3,325
Provision for loan losses covered under FDIC loss share	(144		)		2,672				275				—				—
Wealth Management revenue	1,668				1,832				1,658				1,683				1,767
Noninterest income	(1,067		)		6,894				2,560				3,280				2,114
Noninterest expense	23,427				18,302				18,024				17,965				18,231
Income before income tax expense	9,522				9,121				12,623				6,106				6,687
Net income	7,206				5,832				8,273				4,112				4,986
Net income available to common shareholders	6,570				5,200				7,643				3,486				4,364
Diluted earnings per share	$	0.36			$	0.29			$	0.43			$	0.23			$	0.29
Return on average common equity	12.81		%		10.39		%		18.06		%		9.39		%		11.47		%
Net interest rate margin (fully tax equivalent)	4.35		%		3.79		%		4.75		%		3.58		%		4.09		%
Efficiency ratio	71.41		%		51.56		%		51.17		%		64.92		%		64.55		%
MARKET DATA
Book value per common share	$	11.61			$	11.35			$	11.05			$	10.16			$	9.89
Tangible book value per common share	$	9.38			$	9.11			$	10.74			$	9.79			$	9.67
Market value per share	$	14.80			$	13.59			$	13.53			$	14.07			$	10.46
Period end common shares outstanding	17,774				17,743				17,739				14,941				14,889
Average basic common shares	17,754				17,741				17,140				14,920				14,856
Average diluted common shares	19,226				19,202				18,602				14,936				16,296
ASSET QUALITY
Net charge-offs	$	5,683			$	4,778			$	5,240			$	3,537			$	7,564
Nonperforming loans	41,622				48,038				43,118				43,487				46,357
Nonperforming loans to total loans	1.89		%		2.19		%		2.16		%		2.24		%		2.46		%
Nonperforming assets to total assets*	1.74		%		2.07		%		2.19		%		2.49		%		2.59		%
Allowance for loan losses to total loans	1.80		%		2.07		%		2.11		%		2.20		%		2.26		%
Net charge-offs to average loans (annualized)	1.03		%		0.90		%		1.07		%		0.73		%		1.57		%
CAPITAL
Average common equity to average assets	6.01		%		6.22		%		5.83		%		5.21		%		5.72		%
Tier 1 capital to risk-weighted assets	12.40		%		12.24		%		14.06		%		11.75		%		11.73		%
Total capital to risk-weighted assets	13.78		%		13.70		%		15.61		%		14.04		%		14.11		%
Tier 1 common equity to risk-weighted assets	7.32		%		7.16		%		8.87		%		7.14		%		7.16		%
Tangible common equity to tangible assets	4.99		%		4.88		%		6.53		%		5.03		%		5.15		%
AVERAGE BALANCES
Portfolio loans not covered under FDIC loss share	$	1,872,282			$	1,835,634			$	1,787,008			$	1,769,400			$	1,780,890
Portfolio loans covered under FDIC loss share	314,948				256,381				172,324				184,098				124,315
Loans held for sale	4,886				2,857				2,353				2,361				6,301
Earning assets	2,970,992				2,834,690				2,644,381				2,610,184				2,390,586
Total assets	3,385,845				3,190,490				2,912,331				2,889,430				2,640,855
Deposits	2,838,536				2,661,978				2,416,412				2,391,008				2,169,853
Shareholders' equity	236,548				231,538				202,490				183,244				183,410
LOAN PORTFOLIO
Commercial and industrial	$	763,202			$	706,117			$	688,354			$	612,970			$	593,938
Commercial real estate	811,570				818,578				789,556				780,764				776,268
Construction real estate	140,147				152,464				158,128				176,249				190,285
Residential real estate	171,034				177,871				176,782				174,405				189,484
Consumer and other	11,121				12,926				13,408				16,646				16,376
Portfolio loans covered under FDIC loss share	300,610				326,942				169,113				182,277				121,570
Total loan portfolio	$	2,197,684			$	2,194,898			$	1,995,341			$	1,943,311			$	1,887,921
* Excludes ORE covered by FDIC shared-loss agreements, except for their inclusion in total assets.

8

ENTERPRISE FINANCIAL SERVICES CORP

CONSOLIDATED FINANCIAL SUMMARY (unaudited) (continued)

	For the Quarter ended
					Restated				Restated				Restated				Restated
(in thousands)	Dec 31, 2011				Sep 30, 2011				Jun 30, 2011				Mar 31, 2011				Dec 31, 2010
DEPOSIT PORTFOLIO
Noninterest-bearing accounts	$	585,479			$	557,290			$	473,688			$	448,012			$	366,086
Interest-bearing transaction accounts	253,504				241,815				212,431				198,152				204,687
Money market and savings accounts	1,135,449				1,117,232				960,139				952,798				865,703
Certificates of deposit	816,921				900,925				765,019				831,468				861,245
Total deposit portfolio	$	2,791,353			$	2,817,262			$	2,411,277			$	2,430,430			$	2,297,721
YIELDS (fully tax equivalent)
Loans not covered under FDIC loss share	5.31		%		5.32		%		5.44		%		5.49		%		5.45		%
Loans covered under FDIC loss share	14.62		%		10.16		%		25.33		%		8.53		%		18.74		%
Total portfolio loans	6.65		%		5.91		%		7.19		%		5.78		%		6.32		%
Securities	2.10		%		2.59		%		2.85		%		2.70		%		2.60		%
Federal funds sold	0.24		%		0.27		%		0.25		%		0.26		%		0.26		%
Yield on interest-earning assets	5.32		%		4.84		%		5.90		%		4.79		%		5.40		%
Interest-bearing deposits	0.90		%		1.01		%		1.12		%		1.16		%		1.21		%
Subordinated debt	5.32		%		5.26		%		5.31		%		5.34		%		5.71		%
Borrowed funds	1.84		%		1.94		%		1.99		%		1.89		%		2.32		%
Cost of paying liabilities	1.12		%		1.23		%		1.36		%		1.39		%		1.49		%
Net interest spread	4.20		%		3.61		%		4.54		%		3.40		%		3.91		%
Net interest rate margin	4.35		%		3.79		%		4.75		%		3.58		%		4.09		%
WEALTH MANAGEMENT
Trust Assets under management	$	831,931			$	790,129			$	862,357			$	875,437			$	796,190
Trust Assets under administration	1,602,969				1,439,947				1,579,065				1,600,471				1,498,987

9

ENTERPRISE FINANCIAL SERVICES CORP

CONSOLIDATED FINANCIAL SUMMARY (unaudited) (continued)

RECONCILIATIONS OF U.S. GAAP FINANCIAL MEASURES

	At the Quarter Ended
					Restated				Restated				Restated				Restated
(In thousands)	Dec 31 2011				Sep 30 2011				Jun 30 2011				Mar 31 2011				Dec 31 2010
TIER 1 COMMON EQUITY TO RISK-WEIGHTED ASSETS
Shareholders' equity	$	239,565			$	234,471			$	228,861			$	184,501			$	179,801
Less: Goodwill	(30,334		)		(30,334		)		(3,622		)		(3,622		)		(2,064		)
Less: Intangible assets	(9,285		)		(9,471		)		(1,791		)		(1,921		)		(1,223		)
Less: Unrealized gains; Plus: Unrealized Losses	(3,602		)		(4,718		)		(3,994		)		(245		)		573
Plus: Qualifying trust preferred securities	79,874				78,177				76,306				61,520				59,953
Other	57				59				59				59				59
Tier 1 capital	$	276,275			$	268,184			$	295,819			$	240,292			$	237,099
Less: Preferred stock	(33,293		)		(33,094		)		(32,900		)		(32,707		)		(32,519		)
Less: Qualifying trust preferred securities	(79,874		)		(78,177		)		(76,306		)		(61,520		)		(59,953		)
Tier 1 common equity	$	163,108			$	156,913			$	186,613			$	146,065			$	144,627
Total risk weighted assets determined in accordance with prescribed regulatory requirements	$	2,227,958			$	2,190,880			$	2,104,662			$	2,045,802			$	2,021,136
Tier 1 common equity to risk weighted assets	7.32		%		7.16		%		8.87		%		7.14		%		7.16		%
SHAREHOLDERS' EQUITY TO TANGIBLE COMMON EQUITY AND TOTAL ASSETS TO TANGIBLE ASSETS
Shareholders' equity	$	239,565			$	234,471			$	228,861			$	184,501			$	179,801
Less: Preferred stock	(33,293		)		(33,094		)		(32,900		)		(32,707		)		(32,519		)
Less: Goodwill	(30,334		)		(30,334		)		(3,622		)		(3,622		)		(2,064		)
Less: Intangible assets	(9,285		)		(9,471		)		(1,791		)		(1,921		)		(1,223		)
Tangible common equity	$	166,653			$	161,572			$	190,548			$	146,251			$	143,995
Total assets	$	3,377,779			$	3,348,784			$	2,923,383			$	2,915,645			$	2,800,199
Less: Goodwill	(30,334		)		(30,334		)		(3,622		)		(3,622		)		(2,064		)
Less: Intangible assets	(9,285		)		(9,471		)		(1,791		)		(1,921		)		(1,223		)
Tangible assets	$	3,338,160			$	3,308,979			$	2,917,970			$	2,910,102			$	2,796,912
Tangible common equity to tangible assets	4.99		%		4.88		%		6.53		%		5.03		%		5.15		%

10

ENTERPRISE FINANCIAL SERVICES CORP

CONSOLIDATED FINANCIAL SUMMARY (unaudited) (continued)

IMPACT OF RESTATEMENT ON PRIOR PERIOD BALANCES

	For the Three months ended												At or for the Nine months ended
	September 30, 2011												September 30, 2011
(in thousands, except per share data)	As Previously Reported				Adjustments				As Restated				As Previously Reported				Adjustments				As Restated
Consolidated Statement of Operations
Net income (loss) from continuing operations
Net interest income	$	32,392			$	(5,623	)		$	26,769			$	91,603			$	(11,122	)		$	80,481
Provision for loan losses	5,557				2,515				8,072				13,732				2,515				16,247
Noninterest income	6,562				2,164				8,726				16,651				1,256				17,907
Noninterest expense	18,302				—				18,302				53,791				500				54,291
Income (loss) before income tax	15,095				(5,974		)		9,121				40,731				(12,881		)		27,850
Income tax expense (benefit)	5,394				(2,105		)		3,289				14,069				(4,436		)		9,633
Net income (loss)	9,701				(3,869		)		5,832				26,662				(8,445		)		18,217
Net income (loss) available to common shareholders	9,069				(3,869		)		5,200				24,774				(8,445		)		16,329
Net income (loss) available to common shareholders and assumed conversions	9,440				(3,869		)		5,571				25,887				(8,445		)		17,442
Basic earnings per share	$	0.51			$	(0.22	)		$	0.29			$	1.52			$	(0.52	)		$	1.00
Diluted earnings per share	0.49				(0.20		)		0.29				1.46				(0.48		)		0.98
Consolidated Balance Sheet
Portfolio loans covered under FDIC loss share at fair value													$	343,101			$	(16,159	)		$	326,942
Allowance for loan losses													42,882				2,569				45,451
Portfolio loans, net													2,168,175				(18,728		)		2,149,447
Other real estate covered under FDIC loss share													56,248				(5,055		)		51,193
Accrued interest receivable													8,978				(276		)		8,702
FDIC loss share receivable													175,674				18,542				194,216
Goodwill													47,552				(17,218		)		30,334
Other assets													56,664				1,052				57,716
Total assets													3,370,467				(21,683		)		3,348,784
Total deposits													2,817,405				(143		)		2,817,262
Other liabilities													16,897				(9,548		)		7,349
Total liabilities													3,124,004				(9,691		)		3,114,313
Total shareholders' equity													246,463				(11,992		)		234,471
Total liabilities and shareholders' equity													3,370,467				(21,683		)		3,348,784

11

ENTERPRISE FINANCIAL SERVICES CORP

CONSOLIDATED FINANCIAL SUMMARY (unaudited) (continued)

IMPACT OF RESTATEMENT ON PRIOR PERIOD BALANCES (continued)

	For the Three months ended											At or for the Six months ended
	June 30, 2011											June 30, 2011
(in thousands, except per share data)	As Previously Reported				Adjustments			As Restated				As Previously Reported				Adjustments				As Restated
Consolidated Statement of Operations
Net income (loss) from continuing operations
Net interest income	32,473				(1,469	)		31,004				59,211				(5,499		)		53,712
Provision for loan losses	4,575				—			4,575				8,175				—				8,175
Noninterest income	5,126				(908	)		4,218				10,089				(908		)		9,181
Noninterest expense	18,024				—			18,024				35,489				500				35,989
Income (loss) before income tax	15,000				(2,377	)		12,623				25,636				(6,907		)		18,729
Income tax expense (benefit)	5,118				(768	)		4,350				8,675				(2,331		)		6,344
Net income (loss)	9,882				(1,609	)		8,273				16,961				(4,576		)		12,385
Net income (loss) available to common shareholders	9,252				(1,609	)		7,643				15,705				(4,576		)		11,129
Net income (loss) available to common shareholders and assumed conversions	9,623				(1,609	)		8,014				16,447				(4,576		)		11,871
Basic earnings per share	$	0.54			(0.09	)		$	0.45			$	1.01			(0.30		)		$	0.71
Diluted earnings per share	0.52				(0.09	)		0.43				0.96				(0.26		)		0.70
Consolidated Balance Sheet
Portfolio loans covered under FDIC loss share at fair value												$	180,253			$	(11,140	)		$	169,113
Portfolio loans, net												1,964,324				(11,140		)		1,953,184
FDIC loss share receivable												92,511				(652		)		91,859
Goodwill												3,879				(257		)		3,622
Total assets												2,935,432				(12,049		)		2,923,383
Other liabilities												10,839				(3,926		)		6,913
Total liabilities												2,698,448				(3,926		)		2,694,522
Retained earnings												33,315				(8,123		)		25,192
Total shareholders' equity												236,984				(8,123		)		228,861
Total liabilities and shareholders' equity												2,935,432				(12,049		)		2,923,383

12

ENTERPRISE FINANCIAL SERVICES CORP

CONSOLIDATED FINANCIAL SUMMARY (unaudited) (continued)

IMPACT OF RESTATEMENT ON PRIOR PERIOD BALANCES (continued)

	At or for the three months ended March 31, 2011
(in thousands, except per share data)	As Previously Reported				Adjustments				As Restated
Consolidated Statement of Operations
Net income (loss) from continuing operations
Net interest income	$	26,738			$	(4,030	)		$	22,708
Provision for loan losses	3,600				—				3,600
Noninterest income	4,963				—				4,963
Noninterest expense	17,465				500				17,965
Income (loss) before income tax	10,636				(4,530		)		6,106
Income tax expense (benefit)	3,557				(1,563		)		1,994
Net income (loss)	7,079				(2,967		)		4,112
Net income (loss) available to common shareholders	6,453				(2,967		)		3,486
Net income (loss) available to common shareholders and assumed conversions	6,824				(3,338		)		3,486
Basic earnings per share	$	0.43			$	(0.20	)		$	0.23
Diluted earnings per share	0.42				(0.19		)		0.23
Consolidated Balance Sheet
Portfolio loans covered under FDIC loss share at fair value	$	191,447			$	(9,170	)		$	182,277
Portfolio loans, net	1,909,659				(9,170		)		1,900,489
FDIC loss share receivable	103,529				(244		)		103,285
Goodwill	3,879				(257		)		3,622
Total assets	2,925,316				(9,671		)		2,915,645
Other liabilities	12,047				(3,157		)		8,890
Total liabilities	2,734,301				(3,157		)		2,731,144
Total shareholders' equity	191,015				(6,514		)		184,501
Total liabilities and shareholders' equity	2,925,316				(9,671		)		2,915,645

13

ENTERPRISE FINANCIAL SERVICES CORP

CONSOLIDATED FINANCIAL SUMMARY (unaudited) (continued)

IMPACT OF RESTATEMENT ON PRIOR PERIOD BALANCES (continued)

	For the Three months ended												At or for the Twelve months ended
	December 31, 2010												December 31, 2010
(in thousands, except per share data)	As Previously Reported				Adjustments				As Restated				As Previously Reported				Adjustments				As Restated
Consolidated Statement of Operations
Net income (loss) from continuing operations
Net interest income	$	28,109			$	(3,747	)		$	24,362			$	89,624			$	(5,641	)		$	83,983
Provision for loan losses	3,325				—				3,325				33,735				—				33,735
Noninterest income	3,212				669				3,881				18,360				—				18,360
Noninterest expense	19,649				(1,418		)		18,231				62,908				(696		)		62,212
Income (loss) before income tax	8,347				(1,660		)		6,687				11,341				(4,945		)		6,396
Income tax expense (benefit)	1,921				(220		)		1,701				2,221				(1,398		)		823
Net income (loss)	6,426				(1,440		)		4,986				9,120				(3,547		)		5,573
Net income (loss) available to common shareholders	5,804				(1,440		)		4,364				6,653				(3,547		)		3,106
Basic earnings (loss) per share	$	0.39			$	(0.10	)		$	0.29			$	0.45			$	(0.24	)		$	0.21
Diluted earnings (loss) per share	0.38				(0.09		)		0.29				0.45				(0.24		)		0.21
Consolidated Balance Sheet
Portfolio loans covered under FDIC loss share at fair value													$	126,711			$	(5,141	)		$	121,570
Portfolio loans, net													1,850,303				(5,141		)		1,845,162
FDIC loss share receivable													88,292				(500		)		87,792
Total assets													2,805,840				(5,641		)		2,800,199
Other liabilities													11,569				(2,094		)		9,475
Total liabilities													2,622,492				(2,094		)		2,620,398
Total shareholders' equity													183,348				(3,547		)		179,801
Total liabilities and shareholders' equity													2,805,840				(5,641		)		2,800,199

14