SOUTHWEST BANCORP, INC. REPORTS INCREASED NET INCOME; LOAN GROWTH

CONTACT:	RICK GREEN, PRESIDENT & C.E.O.
	TELEPHONE:	(405) 372-2230
RELEASE DATE:	APRIL 28, 2006

April 28, 2006, Stillwater, Oklahoma . . . . Southwest Bancorp, Inc. (Nasdaq National Market–OKSB), (“Southwest”), today reported net income for the first quarter of 2006 was $6.3 million, a 17% increase from the $5.4 million reported for the first quarter of 2005. Diluted earnings per share were $0.44 compared to $0.43 per share for the 2005 period, an increase of 2%. In late June 2005, Southwest completed a public offering of its common stock to provide funds for future growth. The difference between the percentage growth in net income and growth in earnings per share reflects the effects of the additional shares issued in this offering.

First Quarter 2006 Financial Highlights

•	Portfolio loans of $1.4 billion (loans other than those held for sale); a 3% increase from year-end 2005
•	Shareholders’ equity of $176.9 million, a 4% increase from year-end 2005
•	Net income of $6.3 million; a 17% increase from the first quarter of 2005 and a 37% increase over the fourth quarter of 2005.
•	Diluted earnings per share of 44¢, a 1¢ increase over the first quarter of 2005 (before our 2005 stock offering) and up 13¢, or 42%, over the fourth quarter of 2005.
•	Dividends per share of 8.25¢, an increase of 10% over the first quarter of 2005
•	Book value per share of $12.52, a 3% increase from year-end 2005
•	Return on average equity:	14.48%
•	Return on assets	1.17%
•	GAAP-based efficiency ratio:	50.32%

Selected Financial Information (at period end)

	First Quarter
										Fourth Quarter 2005		% Change
							% Change
(Dollars in thousands except per share data)		2006			2005
Loans held for sale	$	383,164		$	400,179		(4	)%	$	383,447		-	%
Portfolio loans		1,391,817			1,273,599		9			1,352,433		3
Assets		2,145,839			1,994,569		8			2,099,639		2
Deposits		1,699,212			1,628,934		4			1,657,820		2
Shareholders' equity		176,945			129,734		36			170,444		4
Shareholders' equity to assets		8.25	%		6.50	%	27			8.12	%	2
Earnings
Net income	$	6,279		$	5,386		17		$	4,592		37
Diluted earnings per share		0.44			0.43		2			0.31		42
Asset quality
Net charge-offs to average loans		0.39	%		0.86	%				0.63	%
Allowance for loan losses to loans		1.39			1.17					1.37
Nonperforming assets to loans and other real estate		1.82			1.53					1.76
Performance
Return on average assets		1.17			1.08					0.85
Return on average equity		14.48			16.73					10.64
Net interest margin		4.34			4.42					4.22
Efficiency ratio (GAAP-based)		50.32			48.94					49.61

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Rick Green, President and Chief Executive Officer, stated, “The first quarter net income growth was the result of increased yields on loans, portfolio loan growth, our focus on careful management of interest margins and funding, and increased noninterest income. During the quarter, we continued to pursue our long-range strategies for growth and market expansion.”

Lending Activities

Portfolio loans grew by $39.4 million, or 3%, during the first quarter. Portfolio loans exclude loans held for sale, almost all of which are student loans. Southwest expects its portfolio loans to grow at a faster rate during 2006, and plans to reduce the levels of student lending.

Southwest’s Texas and Kansas offices were primarily responsible for the 2006 growth in portfolio loans. At March 31, 2006, Southwest’s four Texas and two Kansas offices accounted for $545.8 million in loans, or 39% of total portfolio loans. Southwest expects to open additional offices in Texas in the months ahead. The timing of new office openings in these targeted markets depends primarily on executive staffing.

At March 31, 2006, student lending balances were up less than 1% from year-end 2005, however, student lending remains an important and profitable part of Southwest’s business. During the first quarter 2006, Southwest originated $217.4 million in student loans for sale, a reduction of $3.5 million, or 2%, from the same period in 2005, and received sales proceeds on student loans of $216.8 million, up $36.8 million, or 20%.

Additional Financial Information for the First Quarter 2006

Net interest income for the first quarter 2006 increased $1.2 million, or 5% from the first quarter 2005, mainly as a result of increased portfolio loan yields and loan volume, offset in part by increased cost of funds on money market accounts and time deposits, and increased levels of interest bearing deposits. Noninterest income for the first quarter 2006 increased $248,000 from the $3.7 million reported for the first quarter 2005 due primarily to a $279,000 increase in service charges and fees.

The provision for loan losses of $2.7 million for the first quarter 2006 decreased $1.6 million, or 38%, from the first quarter 2005. Noninterest expense of $13.2 million for the first quarter 2006 increased $1.1 million, or 9%, from the $12.1 million reported for the first quarter 2005, primarily as a result of a $1.0 million increase in salaries and employee benefits.

Allowance for Loan Losses and Reserve for Unfunded Loan Commitments

At March 31, 2006, the allowance for loan losses was $24.8 million, an increase of $948,000, or 4%, from the allowance for loan losses at year-end 2005. At March 31, 2006, the allowance for loan losses was 1.39% of total loans, compared to 1.37% at year-end 2005. Management believes the amount of the allowance is appropriate, given its systematic methodology for calculating the allowance. Changes in the amount of the allowance resulted from the application of that methodology, which is designed to estimate inherent losses on total loans in the portfolio, including those on nonperforming loans.

At March 31, 2006, the reserve for unfunded loan commitments was $1.5 million, a reduction of $368,000, or 19%, from year-end 2005.

Nonperforming Assets

Nonaccrual loans totaled $23.6 million at March 31, 2006 compared to $22.1 million at December 31, 2005. Total nonperforming loans of $25.3 million increased $1.7 million, or 7%, from year-end 2005, and represented 1.43% of total loans, compared to 1.36% of total loans at year-end 2005. At March 31, 2006, $1.5 million, or 6%, of loans classified as nonperforming were guaranteed by United States agencies or U.S. government sponsored entities.

Mr. Green said, “Much of our business is commercial 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 commercial loans.”

Other real estate at March 31, 2006, was $7.1 million, a reduction of $6,000 from year-end 2005. Total nonperforming assets at March 31, 2006, were $32.4 million, an increase of $1.7 million, or 6%, from year-end 2005.

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Financial Condition

At March 31, 2006, total assets were $2.1 billion, a $46.2 million increase from the end of 2005. Total portfolio loans (loans other than those held for sale) at March 31, 2006 were $1.4 billion, up $39.4 million, or 3%, from year-end 2005. Loans held for sale, which are primarily guaranteed student loans, decreased by $283,000 during the first quarter 2006. Shareholders’ equity at March 31, 2006 totaled $176.9 million, a $6.5 million, or 4%, increase from December 31, 2005. The increase was the result of net income, proceeds of common stock issued through the employee stock option plan, the employee stock purchase plan, and the dividend reinvestment plan, and the tax benefit related to the exercise of stock options partially offset by the declaration of dividends and other comprehensive income (net of tax).

Southwest Bancorp and Subsidiaries

Southwest Bancorp is the financial holding company for Stillwater National Bank and Trust Company (“Stillwater National”), 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 Oklahoma City, Stillwater, Tulsa, and Chickasha, Oklahoma; Austin, Dallas and San Antonio, Texas; and Kansas City and Wichita, Kansas and on the Internet, through SNB DirectBanker®.

At Southwest, we focus on converting our strategic vision into long-term shareholder value. This vision includes long-term goals for increasing our earnings and banking assets from our operations in Oklahoma, Texas, and Kansas that specialize in serving medical, professional, business and commercial real estate customers and from our more traditional, banking operations, including community banking and student lending. Our strategic growth goals include 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 our community banking operations.

Southwest was organized in 1981 as the holding company for Stillwater National, which was chartered in 1894. At March 31, 2006, Southwest had total assets of $2.1 billion, deposits of $1.7 billion, and shareholders’ equity of $176.9 million. Southwest became a public company in late 1993 with assets of approximately $434.0 million. Southwest’s growth to date has been accomplished without banking acquisitions, however acquisitions of other financial institutions and other companies are considered from time to time.

Southwest’s banking philosophy is to provide a high level of customer service, a wide range of financial services, and products responsive to customer needs with a focus on serving healthcare and health professionals, businesses and their managers and owners, and commercial and commercial real estate borrowers. This philosophy has led to the development of a line of deposit, lending, and other financial products that respond to professional and commercial customer needs for speed, efficiency, and information, and which complement more traditional banking products. Southwest has developed a highly automated lockbox, imaging, and information service for commercial customers called “SNB Digital Lockbox,” and deposit products that automatically sweep excess funds from commercial demand deposit accounts and invest them in interest bearing funds. Other specialized financial services include integrated document imaging and cash management services designed to help our customers in the healthcare industry and other record-intensive enterprises operate more efficiently.

Southwest seeks to build close relationships with businesses, professionals and their principals and to service their evolving banking needs throughout their business development and professional lives.

Southwest’s two management consulting subsidiaries complement its banking services and help differentiate Southwest from competitors. Healthcare Strategic Support, Inc. provides management consulting services for physicians, hospitals, and healthcare groups. Business Consulting Group, Inc. provides marketing, strategic, logistics, and operations consulting for both small and large commercial enterprises.

Southwest’s common stock is traded on the NASDAQ National Market under the symbol OKSB.

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 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, 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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SOUTHWEST BANCORP, INC.

UNAUDITED CONSOLIDATED STATEMENTS OF FINANCIAL CONDITION

(Dollars in thousands, except per share data)		March 31, 2006			December 31, 2005
Assets
Cash and cash equivalents	$	44,335		$	50,277
Federal funds sold		8,000			—
Cash and cash equivalents		52,335			50,277
Investment securities:
Held to maturity, fair value $1,528 (2006) and $1,530 (2005)		1,534			1,538
Available for sale, amortized cost $264,669 (2006) and $262,180 (2005)		258,409			256,751
Federal Reserve Bank and Federal Home Loan Bank Stock, at cost		11,915			9,804
Loans held for sale		383,164			383,447
Loans receivable, net of allowance for loan losses of $24,760 (2006) and $23,812 (2005)		1,367,057			1,328,621
Accrued interest receivable		15,173			14,382
Premises and equipment, net		20,862			20,584
Other assets		35,390			34,235
Total assets	$	2,145,839		$	2,099,639
Liabilities and shareholders' equity
Deposits:
Noninterest-bearing demand	$	229,979		$	224,555
Interest-bearing demand		58,188			49,235
Money market accounts		389,688			402,709
Savings accounts		9,233			8,765
Time deposits of $100,000 or more		637,574			608,989
Other time deposits		374,550			363,567
Total deposits		1,699,212			1,657,820
Accrued interest payable		8,906			8,953
Income tax payable		3,022			288
Other liabilities		7,745			11,233
Other borrowings		203,616			204,508
Subordinated debentures		46,393			46,393
Total liabilities		1,968,894			1,929,195
Shareholders' equity:
Common stock – $1 par value; 20,000,000 shares authorized;14,658,042 shares issued and outstanding		14,658			14,658
Paid in capital		45,563			45,672
Retained earnings		129,996			124,882
Accumulated other comprehensive loss		(3,832	)		(3,325	)
Treasury stock, at cost; 524,867 (2006) and 636,125 (2005) shares		(9,440	)		(11,443	)
Total shareholders' equity		176,945			170,444
Total liabilities & shareholders' equity	$	2,145,839		$	2,099,639

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SOUTHWEST BANCORP, INC.

UNAUDITED CONSOLIDATED STATEMENTS OF OPERATIONS

		For the three months ended March 31,
(Dollars in thousands)		2006			2005
Interest income:
Interest and fees on loans	$	36,718		$	29,923
Investment securities		2,670			2,003
Other interest-bearing assets		20			20
Total interest income		39,408			31,946
Interest expense:
Interest-bearing deposits		13,405			7,941
Other borrowings		2,889			1,668
Subordinated debentures		872			1,245
Total interest expense		17,166			10,854
Net interest income		22,242			21,092
Provision for loan losses		2,676			4,309
Other income:
Service charges and fees		2,774			2,495
Other noninterest income		552			372
Gain on sales of loans		905			853
Gain (loss) on investment securities		(263	)		—
Total other income		3,968			3,720
Other expense:
Salaries and employee benefits		7,240			6,212
Occupancy		2,567			2,346
FDIC and other insurance		127			117
Other real estate		108			164
General and administrative		3,148			3,305
Total other expenses		13,190			12,144
Income before taxes		10,344			8,359
Taxes on income		4,065			2,973
Net income	$	6,279		$	5,386

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SOUTHWEST BANCORP, INC.

UNAUDITED AVERAGE BALANCES, YIELDS AND RATES

		For the three months ended March 31,
(Dollars in thousands)		2006					2005
		Average Balance		Average Yield/Rate			Average Balance		Average Yield/Rate
Assets
Total loans	$	1,806,159		8.24	%	$	1,713,666		7.08	%
Investment securities		272,088		3.98			218,570		3.72
Other interest-earning assets		1,918		4.23			3,393		2.39
Total interest-earning assets		2,080,165		7.68			1,935,629		6.69
Other assets		96,913					83,676
Total assets	$	2,177,078				$	2,019,305
Liabilities and shareholders' equity
Interest-bearing demand deposits	$	55,455		0.46	%	$	64,266		0.48	%
Money market accounts		397,990		3.82			377,642		2.04
Savings accounts		8,890		0.23			8,539		0.24
Time deposits		987,972		3.94			943,008		2.56
Total interest-bearing deposits		1,450,307		3.75			1,393,455		2.31
Other borrowings		268,112		4.37			222,330		3.04
Subordinated debentures		46,393		7.52			72,180		6.90
Total interest-bearing liabilities		1,764,812		3.94			1,687,965		2.61
Noninterest-bearing demand deposits		219,108					185,636
Other liabilities		17,266					15,126
Shareholders' equity		175,892					130,578
Total liabilities and shareholders' equity	$	2,177,078				$	2,019,305
Interest rate spread				3.74	%				4.08	%
Net interest margin (1)				4.34	%				4.42	%
Ratio of average interest-earning assets to average interest-bearing liabilities		117.87	%				114.67	%

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

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SOUTHWEST BANCORP, INC.

UNAUDITED CONSOLIDATED FINANCIAL HIGHLIGHTS

		For the three months ended March 31,
(Dollars in thousands, except per share data)		2006			2005
PER COMMON SHARE DATA:
Basic Earnings	$	0.45		$	0.44
Diluted Earnings		0.44			0.43
Book value (at period end)		12.52			10.64
Dividends declared		0.0825			0.0750
WEIGHTED AVERAGE COMMON SHARES OUTSTANDING:
Basic		14,075,998			12,154,300
Diluted		14,406,911			12,579,941
KEY RATIOS:
Return on average assets		1.17	%		1.08	%
Return on average total shareholders' equity		14.48	%		16.73	%
Efficiency ratio		50.32	%		48.94	%
LOAN COMPOSITION AT PERIOD END:
Real estate mortgage:
Commercial	$	573,842		$	527,137
One-to-four family residential		91,007			91,738
Real estate construction		302,698			244,491
Commercial		401,820			394,772
Installment and consumer:
Guaranteed student loans		378,372			390,492
Other		27,242			25,148
Total loans, including loans held for sale	$	1,774,981		$	1,673,778
Less: Allowance for loan losses		(24,760	)		(19,660	)
Total loans, net	$	1,750,221		$	1,654,118

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SOUTHWEST BANCORP, INC.

UNAUDITED CONSOLIDATED FINANCIAL HIGHLIGHTS

(Dollars in thousands, except per share data)		March 31, 2006			December 31 2005			March 31, 2005
ASSET QUALITY AT PERIOD END:
Nonaccrual loans (1)	$	23,555		$	22,099		$	12,737
90 day past due and accruing (2)		1,763			1,486			1,117
Total nonperforming loans (3)	$	25,318		$	23,585		$	13,854
Other real estate owned	$	7,124		$	7,130		$	11,902
Allowance for loan losses as a percentage of total loans		1.39	%		1.37	%		1.17	%
Allowance for loan losses as a percentage of nonperforming loans		97.80	%		100.96	%		141.91	%
Nonperforming loans as a percentage of total loans		1.43	%		1.36	%		0.83	%
Nonperforming assets as a percentage of total loans and other real estate		1.82	%		1.76	%		1.53	%
Total charge-offs	$	1,808		$	12,020		$	3,858
Total recoveries		80			1,056			218
Net charge-offs	$	1,728		$	10,964		$	3,640
Net charge-offs as a percentage of average loans (annualized)		0.39	%		0.63	%		0.86	%
CAPITAL RATIOS AT PERIOD END:
Leverage ratio		10.37	%		10.24	%		8.75	%
Tier I capital ratio		12.62	%		12.95	%		11.03	%
Total capital ratio		13.87	%		14.21	%		13.89	%
Tier I capital	$	225,595		$	218,587		$	176,397
Total capital		248,014			239,759			222,289
Total risk adjusted assets		1,788,001			1,687,519			1,599,780
OTHER MISCELLANEOUS INFORMATION AT PERIOD END:
Goodwill	$	194		$	194		$	194
Mortgage Servicing Rights		1,343			1,353			1,217
Non-mortgage Servicing Rights		53			54			72
Total Intangible Assets	$	1,590		$	1,601		$	1,483
1-4 family mortgage loans serviced for others	$	132,825		$	133,470		$	126,202
Intangible amortization expense		93			379			86
FTE employees		390			381			367
Number of ATMs		297			291			292
Number of branches (4)		13			13			13
Number of loan production offices		2			3			3

(1) The government-guaranteed portion of loans included in these totals were $1.5 million, $1.6 million, and $2.0 million, respectively.

(2) The government-guaranteed portion of loans included in these totals were zero, zero, and $27,000, respectively.

(3) The government-guaranteed portion of loans included in these totals were $1.5 million, $1.6 million, and $2.0 million, respectively.

(4) Includes branches for which regulatory approval has been received, but which were not accepting deposits at period end.

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