On September 22, 2009, the Board of Directors of Pinnacle West Capital Corporation ("Pinnacle West") expanded the number of directors by one and elected Dr. Denis Cortese as a Director, effective January 1, 2010. Dr. Cortese's initial term will extend until the 2010 Annual Meeting of Shareholders. The Board of Directors of Arizona Public Service Company, the principal subsidiary of Pinnacle West, also elected Dr. Cortese to its Board. The Board expects to designate committee assignments for Dr. Cortese at a future meeting.

Dr. Cortese currently serves as the President and Chief Executive Officer of the Mayo Clinic, a position from which he will be retiring in November of 2009.

A copy of the Press Release dated September 23, 2009 announcing Dr. Cortese's election is furnished as Exhibit 99.1 to this Form 8-K.

(d) Exhibits

Exhibit No.           Registrant(s)                          Description
99.1             Pinnacle West Capital         Press Release dated September 23, 2009
                 Corporation
                 Arizona Public Service
                 Company