For additional information:
		Rick Green
		President & CEO
		Kerby E. Crowell
		EVP & CFO
For Immediate Release		(405) 372-2230

Southwest Bancorp Reports Third Quarter Earnings, Increased Reserves

     October 21, 2008, Stillwater, Oklahoma . . . . Southwest Bancorp, Inc. (NASDAQ Global Select Market—OKSB), (“Southwest”), today reported net income of $2.3 million, or $0.16 per diluted share for the third quarter 2008, compared to $5.5 million, or $0.38 per diluted share for the third quarter of 2007. Net income for the nine months ended September 30, 2008 was $11.7 million, or $0.80 per diluted share, compared to $16.9 million, or $1.15 per diluted share, for the prior year. At September 30, 2008, total assets were $2.8 billion compared to $2.6 billion at December 31, 2007.

     “We continue to take strategic actions focused on building long-term shareholder value during these uncertain times,” stated Rick Green, President and Chief Executive Officer. “Throughout this year, we have reduced our quarter to quarter growth in portfolio loans, and plan for a year or more of continued slower growth. We have made significant additions to our allowance for loan losses reflecting our assessment of the emerging effects of national economic conditions even in our relatively strong and stable markets in Texas, Oklahoma, and Kansas. We have increased our capital levels through retained earnings and our July sale of $34.5 million in trust preferred securities. We continue to make liquidity and core funding priorities. We are evaluating additional consumer banking branches in our existing or nearby markets. And, we continue to methodically pursue our long-term strategic vision so that Southwest will be well positioned when the economy gets back on track.”

     Our portfolio loans at quarter end were $2.4 billion, up $58.2 million, or 2%, from June 30, 2008. Approximately 49% of our total portfolio loans at September 30, 2008, were in our Texas or Kansas segments:

• Oklahoma portfolio loans were $962.6 million or 39%,

• Texas portfolio loans were $893.0 million, or 37%,

• Kansas portfolio loans were $288.3 million, or 12%, and

• Other States portfolio loans were $296.2 million, or 12%

     Our strategic vision includes continued emphasis on carefully selected markets in Texas, Oklahoma, and Kansas with emphasis on healthcare and health professionals, businesses and their managers and owners, commercial and commercial real estate borrowers, careful expansion of our community banking operations, and increases in stable funding sources at reasonable cost. During the third quarter, we opened a branch in Edmond, Oklahoma to facilitate our core deposit growth.

     As shown below, the positive earnings effect of our loan growth continued to be offset by the significant margin squeeze that began last year. For the first nine months of 2008, the net interest margin of 3.41% was down 90 basis points from the first nine months of 2007. As a result, net interest income declined $1.8 million, or 3% for the first nine months of 2008.

NASDAQ: OKSB
OKSBP

Southwest Bancorp Reports Earnings, Increased Reserves

	Net Effects of Growth and Margin Squeeze:
	First Nine Months 2008 vs. First Nine Months 2007
	Change in Net Interest Income Due to Changes in:
(Dollars in thousands)	Volume		Rate			Total
Total interest income	$	26,966	$	(33,838	)	$	(6,872	)
Total interest expense		13,907		(19,023	)		(5,116	)
Net interest income	$	13,059	$	(14,815	)	$	(1,756	)

     While the 2008 third quarter net interest margin decreased 86 basis points from third quarter 2007, the margin remains relatively unchanged from second quarter 2008 at 3.39%.

     We increased our provision for loan losses by $6.2 million, or 101%, during the first nine months of 2008 compared to the first nine months of 2007. At September 30, 2008, the allowance for loan losses was $35.8 million, up 21%, from year-end 2007.

     We have no Federal National Mortgage Association (“Fannie Mae”) or Federal Home Loan Mortgage Corporation (“Freddie Mac”) equity securities.

     The validity of our strategic decision not to rely on any significant amounts of residential mortgages and not to make subprime loans was reinforced by recent market events. Subprime lending has never been a part of our strategy, one to four family mortgages are less than 5% of our portfolio, and one to four family residential construction loans are less than 4% of our portfolio.

Capital Raising

     Earlier this year, we determined that raising additional long-term capital was in the best interests of our shareholders. We decided to do so by issuing securities other than common stock, in view of the market conditions for financial stocks. Accordingly, in early July, we completed the issuance of $34.5 million in trust preferred securities in a public offering. Proceeds from the sale are being used to increase our regulatory capital, to fund our loan growth, and for other corporate purposes.

     Please see the following discussion and financial tables and the disclosures under the heading “Forward-Looking Statements” on page 4.

Financial Overview

     Condition: Total assets were $2.8 billion at September 30, 2008, an increase of 10% from $2.6 billion at December 31, 2007. At September 30, 2008 total loans were $2.5 billion versus $2.2 billion at December 31, 2007.

     The allowance for loan losses as a percentage of portfolio loans was 1.47% at September 30, 2008 versus 1.46% at September 30, 2007 and 1.38% at December 31, 2007. The methodology used to determine the appropriate amount of the allowance for loan losses at a particular time includes consideration of risk factors related to Southwest and to our markets, including regular assessments of national and local economic conditions and trends.

     Non-performing assets to total assets were 2.35% at September 30, 2008 compared to 1.29% at September 30, 2007 and 1.26% at December 31, 2007. Of total non-performing assets, 57.8% are real estate construction loans, 19.0% are commercial loans, 18.0% are commercial real estate loans, 4.0% is other real estate owned, and residential real estate mortgages and other consumer loans are less than 1% each. Nonaccrual loans, which comprise the majority of nonperforming assets, were $61.6 million as of September 30, 2008, an increase of $42.0 million or 215% from year end. These loans are carried at their estimated collectible amounts and no longer accrue interest. The increase in nonaccrual loans is primarily due to two lending relationships. Mr. Green said, “Much of our business is commercial real estate lending. As a result, weakness in one or a few large credits can have a significant impact on our nonperforming loan totals. Through the years, however, we have demonstrated the ability to resolve problem construction and commercial real estate loans.” Performing loans considered potential problem loans, which are not included in the past due, nonaccrual, or restructured categories, but for which known information about possible credit problems cause management to be uncertain as to the ability of the borrowers to comply with the present loan repayment terms, amounted to approximately $86.1 million at September 30, 2008, compared to $71.1 million at June 30, 2008 and $61.6 million at year-end 2007. These loans are subject to

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NASDAQ: OKSB
OKSBP

Southwest Bancorp Reports Earnings, Increased Reserves

continuing management attention and are considered by management in determining the level of the allowance for loan losses.

     Total deposits were $2.2 billion at September 30, 2008, up $140.1 million from December 31, 2007. Core deposits were 66.48% of total deposits or $1.5 billion.

     On September 30, 2008, Southwest exceeded all applicable regulatory capital requirements and each of its banking subsidiaries met the criteria for regulatory classification as “well-capitalized”. Designation as a well-capitalized institution under regulations does not constitute a recommendation or endorsement by Federal bank or thrift regulators.

     Year-to-date Results: Net interest income totaled $67.3 million for the first nine months of 2008 compared to $69.1 million for the first nine months of 2007. Year-to-date net interest margin was 3.41% for 2008 compared to 4.31% in 2007. The decrease in net interest income and net interest margin is the result of Southwest’s interest rate sensitivity position and the margin squeeze produced by governmental actions and market conditions. This margin squeeze offset significant positive effects on net interest income from our loan growth. Yields on earning assets decreased by 190 basis points from the prior year while our cost of funds decreased by only 129 basis points, resulting in a 61 basis point decline in net interest spread.

     The provision for loan losses for the first nine months of 2008 was $12.3 million compared to $6.1 million for the first nine months of 2007. Year-to-date as of September 30, 2008, net charge offs totaled $6.1 million, or 0.33% (annualized) of portfolio loans versus net charge offs of $5.1 million, or 0.35% (annualized) of portfolio loans for the same period in the prior year.

     For the first nine months of 2008, noninterest income totaled $12.7 million, compared to $12.4 million for 2007. The slight increase in noninterest income from 2007 was the result of a $1.0 million increase in service charges and fees and a $211,000 increase in other noninterest income, offset by a $512,000 decrease in gain on sale of loans and a $381,000 decrease in the gain on sale of investment securities.

     For the first nine months of 2008, noninterest expense was $48.7 million versus $47.8 million in 2007. The increase from 2007 in noninterest expense is the result of a $1.5 million increase in personnel expense, a $1.0 million increase in FDIC and other insurance, a $723,000 increase in occupancy expense, and a $237,000 increase in other real estate expense (net), offset by a $511,000 decrease in the provision for unfunded loan commitments and a $2.1 million decrease in other general and administrative expenses, which reflects last year’s $2.5 million ATM-related write-off.

     The efficiency ratio was 60.86% for the first nine months of 2008, up from 58.71% in 2007. The year over year increase in the efficiency ratio was due to the combined effect of the increase in Southwest’s operating expenses, without commensurate increase in net interest income, which was constrained by a lower net interest margin.

     Third Quarter Results: Net interest income totaled $23.2 million for the third quarter of 2008 compared to $23.7 million for the third quarter of 2007. Net interest margin was 3.39% for the third quarter of 2008, 4.25% for the third quarter of 2007, and 3.38% for the second quarter of 2008. Yield on earning assets decreased by 212 basis points from the third quarter 2007 while rates paid on interest bearing liabilities decreased by only 160 basis points.

     The provision for loan losses totaled $6.9 million for the third quarter of 2008 compared to $2.1 million for the third quarter of 2007. Net charge offs totaled $2.4 million, or 0.39% (annualized) of portfolio loans at September 30, 2008, compared to $1.9 million, or 0.39% (annualized) of portfolio loans at September 30, 2007.

     Noninterest income totaled $4.1 million for the third quarter of 2008 compared to $3.6 million for the same quarter of 2007. The increase in noninterest income from 2007 was the result of a $301,000 increase in service charges and fee income, a $240,000 increase in other noninterest income, a $53,000 increase in gain on sale of loans, offset by a $158,000 decrease in gain on sale of investment securities.

     Noninterest expense increased $371,000 from the third quarter 2007 to the third quarter of 2008 to $16.5 million. The increase consists of a $454,000 increase in occupancy expense, a $350,000 increase in other general and administrative expenses, and a $335,000 increase in FDIC and other insurance, offset by a $585,000 decrease in the provision for unfunded loan commitments, a $103,000 decrease in salaries and employee benefits, and an $80,000 decrease in other real estate expense (net).

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NASDAQ: OKSB
OKSBP

Southwest Bancorp Reports Earnings, Increased Reserves

     The efficiency ratio for the third quarter of 2008 increased to 60.67% from 59.13% for the third quarter of 2007.

     Certain Legal Matters: As previously disclosed, in December 2006, an armored transportation company failed to deliver to Stillwater National Bank and Trust (“Stillwater National”) cash due to it from certain ATMs owned by one of its subsidiaries, Cash Source, Inc. (“CSI”). In the first quarter of 2007, Southwest recorded a write-off of the $2.5 million receivable. The financial statements also reflect related legal expenses incurred by Southwest of $324,000 during the first nine months of 2008 and approximately $785,000 during the year 2007, of which $720,000 was incurred in the first nine months of 2007. Southwest filed its proof of loss with the insurer on August 6, 2007, which the insurer denied in April 2008. Stillwater National and CSI are pursuing various options for recovery.

     Stillwater National and other Visa USA member banks are obligated to share in costs resulting from litigation against Visa USA, including the costs of the November 9, 2007, settlement of an antitrust lawsuit brought by American Express and potential costs of certain other pending litigation. In the fourth quarter of 2007, Southwest recorded approximately $713,000 as its estimated share of the settlement and other pending litigation expenses relating to these obligations. In March 2008, VISA completed an initial public offering. This transaction allowed VISA to place part of the cash proceeds into an escrow which will be utilized to pay litigation and settlement expenses. Southwest’s portion of this escrow is approximately $566,000 which was reflected in the first quarter 2008 financial statements as a reduction to general and administrative expense and the related payable established in the fourth quarter 2007. These amounts are an estimate and further adjustments may be required.

Southwest Bancorp and Subsidiaries

     Southwest Bancorp is the financial holding company for Stillwater National, Bank of Kansas (“SNB Kansas”), SNB Bank of Wichita (“SNB Wichita”), Healthcare Strategic Support, Inc., and Business Consulting Group, Inc. Through its subsidiaries, Southwest offers commercial and consumer lending, deposit, and investment services, and specialized cash management, consulting, and other financial services from offices in Chickasha, Edmond, Oklahoma City, Stillwater, and Tulsa, Oklahoma; Austin, Dallas, Houston and San Antonio, Texas; and Hutchinson, Kansas City, and Wichita, Kansas, and on the Internet, through SNB DirectBanker®.

     Southwest focuses on converting its strategic vision into long-term shareholder value. Our vision includes an established niche banking model focused on healthcare and commercial real estate financial services in Texas, Oklahoma, and Kansas and a community banking model focused on more traditional banking operations in those states. Southwest’s strategic growth goals include prudent growth from existing and additional offices in carefully selected markets in Texas and other states with concentrations of healthcare and health professionals, businesses, and their managers and owners, and commercial and commercial real estate borrowers, and careful expansion of community banking operations.

     On September 22, 2008, Southwest announced the planned merger of SNB Wichita with SNB Kansas. This merger, which is subject to regulatory approval, is intended to create more convenience for customers and operational efficiencies for Southwest.

     Southwest’s common stock is traded on the NASDAQ Global Select Market under the symbol OKSB. Southwest’s trust preferred securities are traded on the NASDAQ Global Select Market under the symbol OKSBP.

Forward-Looking Statements

     This Press Release includes forward-looking statements, such as: statements of Southwest’s goals, intentions, and expectations; estimates of risks and of future costs and benefits; assessments of the amount and timing of loan growth, performing and problem loan payoffs and loan losses; off-balance sheet risk and market risk; and statements of Southwest’s ability to achieve financial and other goals. These forward-looking statements are subject to significant uncertainties because they are based upon: future interest rates, market behavior, the effects on general economic conditions in our market of recent subprime and other lending problems, and other economic conditions; future laws and regulations; and a variety of other matters. Because of these uncertainties, the actual future results may be materially different from the results indicated by these forward-looking statements. In addition, Southwest’s past growth and performance do not necessarily indicate its future results.

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NASDAQ: OKSB
OKSBP

Southwest Bancorp Reports Earnings, Increased Reserves

Financial Tables

Unaudited Financial Highlights	Table 1
Unaudited Consolidated Statements of Financial Condition	Table 2
Unaudited Consolidated Statements of Operations	Table 3
Unaudited Average Balances, Yields, and Rates-Quarterly	Table 4
Unaudited Average Balances, Yields, and Rates-Year-to-date	Table 5
Unaudited Summary Financial Data by Quarter-2008 and 2007	Table 6
Unaudited Supplemental Analytical Data by Quarter-2008 and 2007	Table 7

5

SOUTHWEST BANCORP, INC.
UNAUDITED FINANCIAL HIGHLIGHTS
(Dollars in thousands except per share) Table 1

	Third Quarter									Second Quarter
							%						%
QUARTERLY HIGHLIGHTS	2008			2007			Change			2008			Change
Operations
Net interest income	$	23,188		$	23,706			(2	)%	$	22,284			4	%
Provision for loan losses		6,855			2,149			219			3,190			115
Noninterest income		4,062			3,626			12			3,959			3
Noninterest expense		16,533			16,162			2			16,332			1
Income before taxes		3,862			9,021			(57	)		6,721			(43	)
Taxes on income		1,556			3,505			(56	)		2,559			(39	)
Net income		2,306			5,516			(58	)		4,162			(45	)
Diluted earnings per share		0.16			0.38			(58	)		0.28			(43	)
Balance Sheet
Total assets		2,832,371			2,386,852			19			2,773,013			2
Loans held for sale		72,248			78,417			(8	)		62,892			15
Portfolio loans		2,440,091			1,933,223			26			2,381,893			2
Total deposits		2,198,719			1,912,719			15			2,211,001			(1	)
Total shareholders’ equity		226,123			213,838			6			224,949			1
Book value per share		15.56			14.92			4			15.49			—
Key Ratios
Net interest margin		3.39	%		4.25	%					3.38	%
Efficiency ratio (GAAP-based)		60.67			59.13						62.23
Total capital to risk-weighted assets		11.88			11.76						10.65
Nonperforming loans to portfolio loans		2.62			1.50						1.35
Shareholders’ equity to total assets		7.98			8.96						8.11
Return on average assets		0.33			0.96						0.62
Return on average equity		3.97			10.29						7.38

	Nine Months
							%
YEAR-TO-DATE HIGHLIGHTS	2008			2007			Change
Operations
Net interest income	$	67,305		$	69,061			(3	)%
Provision for loan losses		12,281			6,117			101
Noninterest income		12,709			12,362			3
Noninterest expense		48,695			47,801			2
Income before taxes		19,038			27,505			(31	)
Taxes on income		7,362			10,648			(31	)
Net income		11,676			16,857			(31	)
Diluted earnings per share		0.80			1.15			(30	)
Balance Sheet
Total assets		2,832,371			2,386,852			19
Loans held for sale		72,248			78,417			(8	)
Portfolio loans		2,440,091			1,933,223			26
Total deposits		2,198,719			1,912,719			15
Total shareholders’ equity		226,123			213,838			6
Book value per share		15.56			14.92			4
Key Ratios
Net interest margin		3.41	%		4.31	%
Efficiency ratio (GAAP-based)		60.86			58.71
Total capital to risk-weighted assets		11.88			11.76
Nonperforming loans to portfolio loans		2.62			1.50
Shareholders’ equity to total assets		7.98			8.96
Return on average assets		0.58			1.02
Return on average equity		6.88			10.88

Balance sheet amounts are as of period end unless otherwise noted.
Please see accompanying tables for additional financial information.

SOUTHWEST BANCORP, INC.
UNAUDITED CONSOLIDATED STATEMENTS OF FINANCIAL CONDITION
(Dollars in thousands, except per share) Table 2

	September 30,			December 31,			September 30,
	2008			2007			2007
Assets
Cash and due from banks	$	36,503		$	45,678		$	30,604
Investment securities:
Held to maturity. Fair value: $7,262 $5,838 $5,301		7,342			5,838			5,335
Available for sale. Amortized cost: $218,974 $232,880 $270,850		217,198			233,531			271,185
Other investments, at cost		17,188			17,239			16,998
Loans held for sale		72,248			66,275			78,417
Loans receivable		2,440,091			2,145,557			1,933,223
Less: Allowance for loan losses		(35,807	)		(29,584	)		(28,314	)
Net loans receivable		2,404,284			2,115,973			1,904,909
Accrued interest receivable		12,530			23,117			22,561
Premises and equipment, net		24,799			24,323			24,064
Other real estate owned		2,685			2,679			1,654
Goodwill		7,071			7,064			6,742
Other intangible assets, net		4,120			4,580			4,335
Other assets		26,403			18,001			20,048
Total assets	$	2,832,371		$	2,564,298		$	2,386,852
Liabilities and shareholders’ equity
Deposits:
Noninterest-bearing demand	$	280,453		$	257,067		$	261,634
Interest-bearing demand		70,471			63,323			63,145
Money market accounts		554,357			541,950			505,192
Savings accounts		14,452			13,032			14,830
Time deposits of $100,000 or more		731,773			690,985			580,850
Other time deposits		547,213			492,222			487,068
Total deposits		2,198,719			2,058,579			1,912,719
Accrued interest payable		9,992			11,441			11,201
Income tax payable		3,828			1,766			2,078
Other liabilities		12,628			10,154			9,776
Other borrowings		299,118			218,356			190,847
Subordinated debentures		81,963			46,393			46,393
Total liabilities		2,606,248			2,346,689			2,173,014
Shareholders’ equity
Common stock — $1 par value; 20,000,000 shares authorized; 14,658,042 shares issued		14,658			14,658			14,658
Paid in capital		45,849			46,478			46,490
Retained earnings		169,026			161,482			158,279
Accumulated other comprehensive income (loss)		(1,075	)		408			209
Treasury stock, at cost, 129,586 300,833 321,991 shares		(2,335	)		(5,417	)		(5,798	)
Total shareholders’ equity		226,123			217,609			213,838
Total liabilities and shareholders’ equity	$	2,832,371		$	2,564,298		$	2,386,852

SOUTHWEST BANCORP, INC.
UNAUDITED CONSOLIDATED STATEMENTS OF OPERATIONS
(Dollars in thousands except per share) Table 3

	For the three months						For the nine months
	ended September 30,						ended September 30,
	2008			2007			2008		2007
Interest income
Loans	$	38,441		$	42,346		$	116,536	$	122,210
Investment securities		2,531			2,816			7,293		8,342
Other interest-earning assets		22			39			70		219
Total interest income		40,994			45,201			123,899		130,771
Interest expense
Interest-bearing deposits		14,398			18,824			47,759		53,940
Other borrowings		1,839			1,715			5,755		4,935
Subordinated debentures		1,569			956			3,080		2,835
Total interest expense		17,806			21,495			56,594		61,710
Net interest income		23,188			23,706			67,305		69,061
Provision for loan losses		6,855			2,149			12,281		6,117
Net interest income after provision for loan losses		16,333			21,557			55,024		62,944
Noninterest income
Service charges and fees		2,849			2,548			8,118		7,089
Gain on sales of loans		601			548			2,044		2,556
Gain (loss) on investment securities		(50	)		108			1,198		1,579
Other noninterest income		662			422			1,349		1,138
Total noninterest income		4,062			3,626			12,709		12,362
Noninterest expense
Salaries and employee benefits		8,863			8,966			26,941		25,449
Occupancy		2,968			2,514			8,028		7,305
FDIC and other insurance		469			134			1,443		397
Other real estate, net		(92	)		(12	)		115		(122	)
General and administrative		4,325			4,560			12,168		14,772
Total noninterest expenses		16,533			16,162			48,695		47,801
Income before taxes		3,862			9,021			19,038		27,505
Taxes on income		1,556			3,505			7,362		10,648
Net income	$	2,306		$	5,516		$	11,676	$	16,857
Basic earnings per common share	$	0.16		$	0.38		$	0.81	$	1.18
Diluted earnings per common share		0.16			0.38			0.80		1.15
Cash dividends declared per share		0.0950			0.0925			0.2850		0.2775

SOUTHWEST BANCORP, INC.
UNAUDITED AVERAGE BALANCES, YIELDS, AND RATES
(Dollars in thousands) Table 4

	For the three months ended September 30,
	2008								2007
	Average					Average			Average					Average
	Balance			Interest		Yield/Rate			Balance			Interest		Yield/Rate
Assets
Loans	$	2,485,617		$	38,441		6.15	%	$	1,925,468		$	42,346		8.73	%
Investment securities		235,428			2,531		4.28			284,394			2,816		3.93
Other interest-earning assets		4,113			22		2.13			3,415			39		4.53
Total interest-earning assets		2,725,158			40,994		5.98			2,213,277			45,201		8.10
Other assets		72,624								72,780
Total assets	$	2,797,782							$	2,286,057
Liabilities and Shareholders’ Equity
Interest-bearing demand deposits	$	75,436		$	147		0.78	%	$	62,667		$	82		0.52	%
Money market accounts		545,520			2,898		2.11			489,514			5,589		4.53
Savings accounts		14,285			17		0.47			13,263			24		0.72
Time deposits		1,272,097			11,336		3.55			1,042,096			13,129		5.00
Total interest-bearing deposits		1,907,338			14,398		3.00			1,607,540			18,824		4.65
Other borrowings		275,365			1,839		2.66			149,952			1,715		4.54
Subordinated debentures		81,122			1,569		7.74			46,393			956		8.24
Total interest-bearing liabilities		2,263,825			17,806		3.13			1,803,885			21,495		4.73
Noninterest-bearing demand deposits		278,565								246,607
Other liabilities		24,250								22,904
Shareholders’ equity		231,142								212,661
Total liabilities and shareholders’ equity	$	2,797,782							$	2,286,057
Net interest income and spread				$	23,188		2.85	%				$	23,706		3.37	%
Net interest margin (1)							3.39	%							4.25	%
Average interest-earning assets to average interest-bearing liabilities		120.38	%							122.70	%

(1) Net interest margin = annualized net interest income / average interest-earning assets

Table 5

SOUTHWEST BANCORP, INC.
UNAUDITED AVERAGE BALANCES, YIELDS, AND RATES
(Dollars in thousands)

	For the nine months ended September 30,
	2008								2007
	Average					Average			Average					Average
	Balance			Interest		Yield/Rate			Balance			Interest		Yield/Rate
Assets
Loans	$	2,401,162		$	116,536		6.48	%	$	1,856,068		$	122,210		8.80	%
Investment securities		234,894			7,293		4.15			278,090			8,342		4.01
Other interest-earning assets		3,430			70		2.73			5,945			219		4.93
Total interest-earning assets		2,639,486			123,899		6.27			2,140,103			130,771		8.17
Other assets		72,084								73,385
Total assets	$	2,711,570							$	2,213,488
Liabilities and Shareholders’ Equity
Interest-bearing demand deposits	$	75,813		$	454		0.80	%	$	62,367		$	261		0.56	%
Money market accounts		546,560			10,488		2.56			428,597			14,294		4.46
Savings accounts		13,780			58		0.56			11,795			65		0.74
Time deposits		1,237,196			36,759		3.97			1,055,156			39,320		4.98
Total interest-bearing deposits		1,873,349			47,759		3.41			1,557,915			53,940		4.63
Other borrowings		266,367			5,755		2.89			140,110			4,935		4.71
Subordinated debentures		58,054			3,080		7.07			46,393			2,835		8.15
Total interest-bearing liabilities		2,197,770			56,594		3.44			1,744,418			61,710		4.73
Noninterest-bearing demand deposits		265,245								240,688
Other liabilities		21,826								21,158
Shareholders’ equity		226,729								207,224
Total liabilities and shareholders’ equity	$	2,711,570							$	2,213,488
Net interest income and spread				$	67,305		2.83	%				$	69,061		3.44	%
Net interest margin (1)							3.41	%							4.31	%
Average interest-earning assets to average interest-bearing liabilities		120.10	%							122.68	%

(1) Net interest margin = annualized net interest income / average interest-earning assets

Table 6

SOUTHWEST BANCORP, INC.
UNAUDITED QUARTERLY SUMMARY FINANCIAL DATA
(Dollars in thousands except per share)

	2008							2007
	Sep. 30			Jun. 30		Mar. 31		Dec. 31		Sep. 30			Jun. 30			Mar. 31
OPERATIONS
Interest income:
Loans	$	38,441		$	37,485	$	40,610	$	43,549	$	42,346		$	39,578		$	40,286
Investment securities		2,531			2,426		2,336		2,713		2,816			2,847			2,679
Other interest-earning assets		22			20		28		35		39			115			65
Total interest income		40,994			39,931		42,974		46,297		45,201			42,540			43,030
Interest expense:
Interest bearing demand deposits		147			166		141		94		82			98			81
Money market accounts		2,898			3,062		4,528		5,370		5,589			4,743			3,962
Savings accounts		17			19		22		22		24			21			20
Time deposits of $100,000 or more		6,879			7,051		7,865		7,873		7,445			7,781			8,132
Other time deposits		4,457			4,809		5,698		5,840		5,684			5,250			5,028
Total interest-bearing deposits		14,398			15,107		18,254		19,199		18,824			17,893			17,223
Other borrowings		1,839			1,887		2,029		2,620		1,715			1,089			2,131
Subordinated debentures		1,569			653		858		942		956			946			933
Total interest expense		17,806			17,647		21,141		22,761		21,495			19,928			20,287
Net interest income		23,188			22,284		21,833		23,536		23,706			22,612			22,743
Provision for loan losses		6,855			3,190		2,236		2,464		2,149			2,107			1,861
Noninterest income:
Service charges and fees		2,849			2,812		2,457		2,831		2,548			2,306			2,235
Gain on sales of loans		601			603		840		783		548			800			1,208
Gain (loss) on investment securities		(50	)		3		1,245		5		108			1,919			(448	)
Other noninterest income		662			541		146		452		422			400			316
Total noninterest income		4,062			3,959		4,688		4,071		3,626			5,425			3,311
Noninterest expense:
Salaries and employee benefits		8,863			8,856		9,222		9,838		8,966			8,358			8,125
Occupancy		2,968			2,602		2,458		2,540		2,514			2,388			2,403
FDIC and other insurance		469			521		453		225		134			140			123
Other real estate, net		(92	)		197		10		64		(12	)		(41	)		(69	)
Unfunded loan commitment		90			15		145		368		675			151			(65	)
Other general and administrative		4,235			4,141		3,542		4,638		3,885			3,812			6,314
Total noninterest expenses		16,533			16,332		15,830		17,673		16,162			14,808			16,831
Income before taxes		3,862			6,721		8,455		7,470		9,021			11,122			7,362
Taxes on income		1,556			2,559		3,247		2,949		3,505			4,281			2,862
Net income	$	2,306		$	4,162	$	5,208	$	4,521	$	5,516		$	6,841		$	4,500
PER SHARE DATA
Basic earnings per common share	$	0.16		$	0.29	$	0.36	$	0.32	$	0.38		$	0.48		$	0.32
Diluted earnings per common share		0.16			0.28		0.36		0.31		0.38			0.47			0.31
Cash dividends declared per share		0.0950			0.0950		0.0950		0.0925		0.0925			0.0925			0.0925
Book value per share		15.56			15.49		15.43		15.16		14.92			14.53			14.14
Tangible book value per share		15.08			15.00		14.95		14.66		14.45			14.44			14.05
Weighted average shares outstanding:
Basic		14,527,893			14,526,038		14,413,686		14,353,910		14,335,008			14,299,111			14,263,698
Diluted		14,676,082			14,680,262		14,608,190		14,584,878		14,612,732			14,644,863			14,642,913
OTHER FINANCIAL DATA
Investment securities	$	241,728		$	234,429	$	236,059	$	256,608	$	293,518		$	278,330		$	274,402
Loans held for sale		72,248			62,892		66,364		66,275		78,417			73,011			108,025
Portfolio loans		2,440,091			2,381,893		2,287,606		2,145,557		1,933,223			1,769,528			1,667,195
Total loans		2,512,339			2,444,785		2,353,970		2,211,832		2,011,640			1,842,539			1,775,220
Total assets		2,832,371			2,773,013		2,670,580		2,564,298		2,386,852			2,196,005			2,194,179
Total deposits		2,198,719			2,211,001		2,094,927		2,058,579		1,912,719			1,823,806			1,803,181
Other borrowings		299,118			265,614		282,513		218,356		190,847			95,561			123,212
Subordinated debentures		81,963			46,393		46,393		46,393		46,393			46,393			46,393
Total shareholders’ equity		226,123			224,949		224,155		217,609		213,838			208,185			201,777
Mortgage servicing portfolio		153,250			147,672		145,028		141,680		136,294			134,444			134,259

Continued

SOUTHWEST BANCORP, INC.
UNAUDITED QUARTERLY SUMMARY FINANCIAL DATA
(Dollars in thousands except per share) Table 6
Continued

	2008									2007
	Sep. 30			Jun. 30			Mar. 31			Dec. 31			Sep. 30			Jun. 30			Mar. 31
PERFORMANCE RATIOS
Return on average assets (annualized)		0.33	%		0.62	%		0.80	%		0.72	%		0.96	%		1.28	%		0.83	%
Return on average equity (annualized)		3.97			7.38			9.43			8.24			10.29			13.26			9.04
Return on average tangible equity (annualized)		4.26			7.86			9.94			8.86			10.88			13.70			9.23
Net interest margin		3.39			3.38			3.45			3.89			4.25			4.36			4.34
Dividends declared to net income		59.85			33.16			26.37			29.37			24.04			19.37			29.32
Effective tax rate		40.29			38.07			38.40			39.48			38.85			38.49			38.88
Efficiency ratio		60.67			62.23			59.69			64.02			59.13			52.82			64.60
ASSET QUALITY RATIOS
Nonperforming assets to portfolio loans and other real estate owned		2.72	%		1.45	%		1.41	%		1.50	%		1.59	%		1.45	%		1.88	%
Nonperforming loans to portfolio loans		2.62			1.35			1.27			1.38			1.50			1.37			1.77
Net loan charge-offs to average total loans		0.38			0.30			0.33			0.22			0.39			0.40			0.31
Allowance for loan losses to total loans		1.43			1.28			1.27			1.34			1.41			1.52			1.56
Allowance for loan losses to portfolio loans		1.47			1.32			1.31			1.38			1.46			1.59			1.66
Allowance for loan losses to nonperforming loans		56.07			97.62			103.49			100.04			97.32			115.65			94.18
CAPITAL RATIOS
Average total shareholders’ equity to average assets		8.26	%		8.35	%		8.49	%		8.80	%		9.30	%		9.64	%		9.15	%
Leverage ratio		10.51			9.66			9.91			10.23			10.92			11.73			11.12
Tier 1 capital to risk-weighted assets		10.49			9.40			9.47			9.71			10.49			11.84			12.44
Total capital to risk-weighted assets		11.88			10.65			10.69			10.97			11.76			13.13			13.68
SEGMENT LOANS**
Oklahoma banking	$	962,611		$	965,952		$	943,331		$	876,085		$	844,859		$	804,906		$	766,990
Texas banking		892,998			857,160			797,700			759,389			644,749			567,236			507,384
Kansas banking		288,268			277,887			287,339			282,846			251,131			198,228			206,405
Other states banking		296,214			280,894			259,236			227,237			192,484			199,158			186,416
Subtotal		2,440,091			2,381,893			2,287,606			2,145,557			1,933,223			1,769,528			1,667,195
Secondary market		72,248			62,892			66,364			66,275			78,417			73,011			108,025
Total loans	$	2,512,339		$	2,444,785		$	2,353,970		$	2,211,832		$	2,011,640		$	1,842,539		$	1,775,220
SEGMENT NET INCOME**
Oklahoma banking	$	3,295		$	2,923		$	2,503		$	3,080		$	3,759		$	4,820		$	4,278
Texas banking		1,332			1,777			2,406			1,701			1,638			1,568			1,643
Kansas banking		(1,336	)		(40	)		458			82			243			326			208
Other states banking		848			1,028			969			225			768			930			240
Subtotal		4,139			5,688			6,336			5,088			6,408			7,644			6,369
Secondary market		(149	)		40			(174	)		114			33			197			753
Other operations		(1,684	)		(1,566	)		(954	)		(681	)		(925	)		(1,000	)		(2,622	)
Total net income	$	2,306		$	4,162		$	5,208		$	4,521		$	5,516		$	6,841		$	4,500
OFFICES AND EMPLOYEES
FTE Employees		458			463			467			489			484			457			443
ATM’s		41			40			40			43			43			38			39
Branches		18			17			17			17			17			15			15
Loan production offices		3			3			3			3			3			3			3
Assets per employee	$	6,184		$	5,989		$	5,719		$	5,244		$	4,932		$	4,805		$	4,953

Balance sheet amounts are as of period end unless otherwise noted.

**

In first quarter 2008, Southwest changed its segment disclosures to report Texas, Kansas and Other states separately. Portfolio loans are allocated based upon the state of the borrower, or the location of the real estate in the case of real estate loans. Loans included in the “Other states banking” segment are portfolio loans attributable to states other than Oklahoma, Texas, or Kansas, and primarily consist of healthcare and commercial real estate credits. These out of state loans are administered by offices in Oklahoma, Texas, or Kansas.

SOUTHWEST BANCORP, INC.	Table 7
UNAUDITED QUARTERLY SUPPLEMENTAL ANALYTICAL DATA
(Dollars in thousands except per share)

	2008									2007
	Sep. 30			Jun. 30			Mar. 31			Dec. 31			Sep. 30			Jun. 30			Mar. 31
LOAN COMPOSITION
Real estate mortgage:
Commercial	$	1,077,601		$	991,679		$	846,757		$	750,047		$	608,409		$	564,813		$	582,440
One-to-four family residential		116,270			118,056			110,938			111,085			112,407			90,916			83,312
Real estate construction		634,339			666,756			744,090			724,929			659,214			617,993			517,199
Commercial		574,087			566,830			544,183			521,501			517,658			465,588			457,838
Installment and consumer:
Guaranteed student loans		67,610			57,413			63,706			61,555			73,810			68,117			101,905
Other		42,432			44,051			44,296			42,715			40,142			35,112			32,526
Total loans, including held for sale		2,512,339			2,444,785			2,353,970			2,211,832			2,011,640			1,842,539			1,775,220
Less allowance for loan losses		(35,807	)		(31,341	)		(29,950	)		(29,584	)		(28,314	)		(28,054	)		(27,728	)
Total loans, net	$	2,476,532		$	2,413,444		$	2,324,020		$	2,182,248		$	1,983,326		$	1,814,485		$	1,747,492
By statement of condition category:
Loans held for sale:
Student loans	$	67,610		$	57,413		$	63,706		$	61,555		$	73,810		$	68,117		$	101,905
One-to-four family residential		3,500			4,283			1,417			3,442			3,293			3,382			4,113
Other		1,138			1,196			1,241			1,278			1,314			1,512			2,007
Total loans held for sale		72,248			62,892			66,364			66,275			78,417			73,011			108,025
Portfolio loans		2,440,091			2,381,893			2,287,606			2,145,557			1,933,223			1,769,528			1,667,195
Total loans before allowance	$	2,512,339		$	2,444,785		$	2,353,970		$	2,211,832		$	2,011,640		$	1,842,539		$	1,775,220
DEPOSIT COMPOSITION
Non-interest bearing demand	$	280,453		$	299,699		$	248,315		$	257,067		$	261,634		$	248,285		$	251,777
Interest-bearing demand		70,471			81,415			71,450			63,323			63,145			63,758			63,741
Money market accounts		554,357			548,099			553,850			541,950			505,192			487,096			394,668
Savings accounts		14,452			13,809			13,808			13,032			14,830			11,017			11,196
Time deposits of $100,000 or more		731,773			740,174			690,421			690,985			580,850			571,584			646,668
Other time deposits		547,213			527,805			517,083			492,222			487,068			442,066			435,131
Total deposits	$	2,198,719		$	2,211,001		$	2,094,927		$	2,058,579		$	1,912,719		$	1,823,806		$	1,803,181
NONPERFORMING ASSETS
Nonaccrual loans	$	61,557		$	30,861		$	26,134		$	19,534		$	26,291		$	22,633		$	26,978
90 days past due and accruing		2,299			1,242			2,807			10,037			2,803			1,625			2,462
Total nonperforming loans		63,856			32,103			28,941			29,571			29,094			24,258			29,440
Other real estate owned		2,685			2,523			3,328			2,679			1,654			1,508			1,869
Total nonperforming assets	$	66,541		$	34,626		$	32,269		$	32,250		$	30,748		$	25,766		$	31,309
Potential nonperforming loans	$	86,070		$	71,070		$	69,588		$	61,633		$	70,389		$	69,595		$	52,335
ALLOWANCE ACTIVITY
Balance, beginning of period	$	31,341		$	29,950		$	29,584		$	28,314		$	28,054		$	27,728		$	27,293
Charge offs		2,752			1,892			2,044			1,290			2,105			1,875			1,728
Recoveries		363			93			174			96			216			94			302
Net charge offs		2,389			1,799			1,870			1,194			1,889			1,781			1,426
Provision for loan losses		6,855			3,190			2,236			2,464			2,149			2,107			1,861
Balance, end of period	$	35,807		$	31,341		$	29,950		$	29,584		$	28,314		$	28,054		$	27,728
REGULATORY CAPITAL DATA
Tier I capital	$	293,141		$	261,354		$	258,272		$	251,980		$	248,961		$	251,460		$	244,862
Total capital		332,012			296,166			291,638			284,730			279,031			278,799			269,513
Total risk adjusted assets		2,793,843			2,780,538			2,727,853			2,595,090			2,374,152			2,123,862			1,967,001
COMMON STOCK
Issued		14,658,042			14,658,042			14,658,042			14,658,042			14,658,042			14,658,042			14,658,042
Less treasury shares		(129,586	)		(131,566	)		(133,605	)		(300,833	)		(321,991	)		(329,570	)		(385,632	)
Outstanding shares		14,528,456			14,526,476			14,524,437			14,357,209			14,336,051			14,328,472			14,272,410
INTANGIBLE ASSET DATA
Goodwill	$	7,071		$	7,071		$	7,071		$	7,064		$	6,742		$	1,213		$	1,213
Core deposit intangible		2,693			2,792			2,893			3,053			2,879			1,466			1,531
Mortgage servicing rights		1,417			1,354			1,299			1,513			1,440			1,428			1,413
Nonmortgage servicing rights		10			11			13			14			16			32			37
Total intangible assets	$	11,191		$	11,228		$	11,276		$	11,644		$	11,077		$	4,139		$	4,194
Intangible amortization expense	$	212		$	215		$	257		$	159		$	161		$	165		$	162

Balance sheet amounts are as of period end unless otherwise noted.