Pinnacle West Capital Corp. (NYSE: PNW) announced today that it plans to release its second-quarter results before the U.S. financial markets open on Thursday, August 2, 2012. That same day at 12:00 noon (ET), the Company also will host a live webcast of management’s conference call to discuss the Company’s 2012 second-quarter results, as well as recent developments. The webcast can be accessed at pinnaclewest.com/presentations and will be available for replay on the website for 30 days. To access the live conference call by telephone, dial (877) 407-8035 or (201) 689-8035 for international callers. A replay of the call also will be available until 11:59 p.m. (ET), Thursday, August 9, 2012, by calling (877) 660-6853 in the U.S. and Canada or (201) 612-7415 internationally and entering account number 286, followed by conference ID number 396789. General Information Pinnacle West Capital, an energy holding company based in Phoenix, has consolidated assets of about $13.2 billion, more than 6,300 megawatts of generating capacity and about 6,700 employees in Arizona and New Mexico. Through its principal subsidiary, Arizona Public Service, the Company provides retail electricity service to more than 1.1 million Arizona homes and businesses. For more information about Pinnacle West, visit the Company’s website at pinnaclewest.com.