UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 18, 2006 WESTERN ALLIANCE BANCORPORATION (Exact name of registrant as specified in its charter) Nevada 001-32550 88-0365922 (State or other jurisdiction (Commission (IRS Employer of incorporation) File Number) Identification No.) 2700 West Sahara Avenue, Las Vegas, Nevada 89102 (Address of principal executive offices) (Zip Code) Registrant's telephone number, including area code: (702) 248-4200 Not Applicable (Former name or former address, if changed since last report) Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: |_| Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) |_| Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) |_| Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) |_| Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) Rule 425, Rule 14a-12 and Instruction 2 to Rule 14d-2(b)(2) -------------------------------------------------------------------------------- Item 2.02. Results of Operations and Financial Condition. On April 18, 2006, Western Alliance Bancorporation issued a press release describing its results of operations for the fiscal quarter ended March 31, 2006. That press release is attached hereto as Exhibit 99.1. Item 9.01. Financial Statements and Exhibits. (c) Exhibits. Exhibit No. Description ------------ ----------------------------------------------------------- 99.1 Press Release dated April 18, 2006. -------------------------------------------------------------------------------- SIGNATURES Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized. WESTERN ALLIANCE BANCORPORATION (Registrant) /s/ Dale Gibbons -------------------------------- Dale Gibbons Executive Vice President and Chief Financial Officer Date: April 18, 2006