PHOENIX - Pinnacle West Capital Corporation (NYSE: PNW) announced today that it expects to release first-quarter results prior to market open on Tuesday, May 9, 2006.

The Company also will host a simultaneous conference call and web cast to discuss its 2006 first-quarter results and recent developments at 1:00 p.m. (ET) Tuesday, May 9, 2006. The web cast can be accessed at www.pinnaclewest.com/presentations and will be available for replay on the web site for 30 days. To access the live conference call by telephone, dial (877) 356-3961 and enter reservation number 8073391. A replay of the call also will be available until 11:55 p.m. (ET), Tuesday, May 16, 2006, by calling (800) 642-1687 in the U.S. and Canada or (706) 645-9291 internationally and entering the same reservation number as above.

Pinnacle West is a Phoenix-based company with consolidated assets of about $11 billion. Through its subsidiaries, the Company generates, sells and delivers electricity and sells energy-related products and services to retail and wholesale customers in the western United States.   It also develops residential, commercial and industrial real estate projects.

Contacts

Media:
Alan Bunnell, (602) 250-3376

Analyst:
Rebecca Hickman, (602) 250-5668
Lisa Malagon, (602) 250-5671