UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 13G UNDER THE SECURITIES EXCHANGE ACT OF 1934 ANNUAL FILING PINNACLE WEST CAPITAL CORP. (NAME OF ISSUER) COMMON STOCK (TITLE CLASS OF SECURITIES) 723484101 (CUSIP NUMBER) 12/31/2009 (DATE OF EVENT WHICH REQUIRES FILING OF THIS STATEMENT) CHECK THE APPROPRIATE BOX TO DESIGNATE THE RULE PURSUANT TO WHICH THIS SCHEDULE IS FILED: (X) RULE 13D-1(B) ( ) RULE 13D-1(C) ( ) RULE 13D-1(D) *THE REMAINDER OF THIS COVER PAGE SHALL BE FILLED OUT FOR A REPORTING PERSON'S INITIAL FILING ON THIS FORM WITH RESPECT TO THE SUBJECT CLASS OF SECURITIES, AND FOR ANY SUBSEQUENT AMENDMENT CONTAINING INFORMATION WHICH WOULD ALTER THE DISCLOSURES PROVIDED IN A PRIOR COVER PAGE. THE INFORMATION REQUIRED IN THE REMAINDER OF THIS COVER PAGE SHALL NOT BE DEEMED TO BE "FILED" FOR THE PURPOSE OF SECTION 18 OF THE SECURITIES EXCHANGE ACT OF 1934 ("ACT") OR OTHERWISE SUBJECT TO THE LIABILITIES OF THAT SECTION OF THE ACT BUT SHALL BE SUBJECT TO ALL OTHER PROVISIONS OF THE ACT (HOWEVER, SEE THE NOTES). EXPLANATORY NOTE: THE SECURITIES REPORTED IN THIS SCHEDULE 13G WERE FORMERLY REPORTED AS BENEFICIALLY OWNED BY STATE STREET CORPORATION'S WHOLLY OWNED SUBSIDIARY, STATE STREET BANK AND TRUST COMPANY, AND ARE NOW BEING REPORTED AS BENEFICIALLY OWNED BY STATE STREET CORPORATION PURSUANT TO RULE 13D-1(B)(II)(G) PROMULGATED UNDER THE SECURITIES EXCHANGE ACT OF 1934. CUSIP NO. 723484101 13G PAGE 2 OF 8 PAGES 1. NAME OF REPORTING PERSON: STATE STREET CORPORATION I.R.S. IDENTIFICATION NO. OF ABOVE PERSON: 04-2456637 2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP NOT APPLICABLE A __ B __ 3. SEC USE ONLY 4. CITIZENSHIP OR PLACE OF ORGANIZATION BOSTON, MASSACHUSETTS 5. SOLE VOTING POWER 0 SHARES 6. SHARED VOTING POWER 7,537,794 SHARES 7. SOLE DISPOSITIVE POWER 0 SHARES 8. SHARED DISPOSITIVE POWER 7,537,794 SHARES 9. AGGREGATED AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 7,537,794 SHARES 10. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES NOT APPLICABLE 11. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9 7.4% 12. TYPE OF REPORTING PERSON HC CUSIP NO. 723484101 13G PAGE 3 OF 8 PAGES 1. NAME OF REPORTING PERSON STATE STREET BANK AND TRUST COMPANY, ACTING IN VARIOUS CAPACITIES I.R.S. IDENTIFICATION NO. OF ABOVE PERSON 04-1867445 2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP NOT APPLICABLE A __ B __ 3. SEC USE ONLY 4. CITIZENSHIP OR PLACE OF ORGANIZATION MASSACHUSETTS NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH 5. SOLE VOTING POWER 0 SHARES 6. SHARED VOTING POWER 5,656,511 SHARES 7. SOLE DISPOSITIVE POWER 0 SHARES 8. SHARED DISPOSITIVE POWER 5,656,511 SHARES 9. AGGREGATED AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 5,656,511 SHARES 10. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES NOT APPLICABLE 11. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9 5.6% 12. TYPE OF REPORTING PERSON BK CUSIP NO. 723484101 13G PAGE 4 OF 8 PAGES ITEM 1. (A) NAME OF ISSUER PINNACLE WEST CAPITAL CORP. (B) ADDRESS OF ISSUER'S PRINCIPAL EXECUTIVE OFFICES 400 NORTH FIFTH STREET PHOENIX AZ 85004 ITEM 2. (A) NAME OF PERSON FILING STATE STREET CORPORATION AND ANY OTHER REPORTING PERSON IDENTIFIED ON THE SECOND PART OF THE COVER PAGES HERETO (B) ADDRESS OF PRINCIPAL BUSINESS OFFICE OR, IF NONE, RESIDENCE STATE STREET FINANCIAL CENTER ONE LINCOLN STREET BOSTON, MA 02111 (FOR ALL REPORTING PERSONS) (C) CITIZENSHIP: SEE ITEM 4 (CITIZENSSHIP OR PLACE OF ORGANIZATION) OF COVER PAGES (D) TITLE OF CLASS OF SECURITIES COMMON STOCK, $1.00 PAR VALUE PER SHARE (E) CUSIP NUMBER: 723484101 ITEM 3. IF THIS STATEMENT IS FILED PURSUANT TO RULE 13D-1(B), OR 13D-2(B), OR (C), CHECK WHETHER THE PERSON FILING IS A: SEE ITEM 12(TYPE OF REPORTING PERSON) OF THE COVER PAGE FOR EACH REPORTING PERSON AND THE TABLE BELOW, WHICH EXPLAINS THE MEANING OF THE TWO LETTER SYMBOLS APPEARING IN ITEM 12 OF THE COVER PAGES. SYMBOL CATEGORY BK BANK AS DEFINED IN SECTION 3(A)(6) OF THE ACT. IC INSURANCE COMPANY AS DEFINED IN SECTION 3 (A)(19) OF THE ACT. CUSIP NO. 723484101 13G PAGE 5 OF 8 PAGES IC INVESTMENT COMPANY REGISTERED UNDER SECTION 8 OF THE INVESTMENT COMPANY ACT OF 1940. IA AN INVESTMENT ADVISER IN ACCORDANCE WITH RULE 13D-1(B)(1)(II)(E). EP AN EMPLOYEE BENEFIT PLAN OR ENDOWMENT FUND IN ACCORDANCE WITH RULE 13D-1(B)(1)(II)(F). HC A PARENT HOLDING COMPANY OR CONTROL PERSON IN ACCORDANCE WITH RULE 13D-1(B)(1)(II)(G). SA A SAVINGS ASSOCIATIONS AS DEFINED IN SECTION 3(B) OF THE FEDERAL DEPOSIT INSURANCE ACT (12 U.S.C. 1813). CP A CHURCH PLAN THAT IS EXCLUDED FROM THE DEFINITION OF AN INVESTMENT COMPANY UNDER SECTION 3(C)(14)OF THE INVESTMENT COMPANY ACT OF 1940. ITEM 4. OWNERSHIP THE INFORMATION SET FORTH IN ROWS 5 THROUGH 11 OF THE COVER PAGE HERETO FOR EACH OF THE REPORTING PERSONS IS INCORPORATED HEREIN BY REFERENCE. THE PERCENTAGE AMOUNT SET FORTH IN ROW 11 FOR ALL COVER PAGES FILED HEREWITH IS CALCULATED BASED UPON THE 101,281,436 SHARES OF COMMON STOCK ISSUED AND OUTSTANDING AS REPORTED BY PINNACLE WEST CAPITAL CORPORATION IN ITS FORM 10-Q FOR THE QUARTERLY PERIOD ENDED SEPTEMBER 30, 2009. THIS REPORT IS NOT AN ADMISSION THAT STATES THAT ANY OF THE REPORTING PERSONS IS THE BENEFICIAL OWNER OF ANY SECURITIES COVERED BY THIS REPORT, AND THE REPORTING PERSONS EXPRESSLY DISCLAIMS BENEFICIAL OWNERSHIP OF ALL SHARES REPORTED HEREIN PURSUANT TO RULE 13D-4. ITEM 5. OWNERSHIP OF FIVE PERCENT OR LESS OF A CLASS NOT APPLICABLE ITEM 6. OWNERSHIP OF MORE THAN FIVE PERCENT ON BEHALF OF ANOTHER PERSON. NOT APPLICABLE CUSIP NO. 723484101 13G PAGE 6 OF 8 PAGES ITEM 7. IDENTIFICATION AND CLASSIFICATION OF THE SUBSIDIARY WHICH ACQUIRED THE SECURITY BEING REPORTED ON BY THE PARENT HOLDING COMPANY OR CONTROL PERSON SEE EXHIBIT 1 ATTACHED HERETO ITEM 8. IDENTIFICATION AND CLASSIFICATION OF MEMBERS OF THE GROUP NOT APPLICABLE ITEM 9. NOTICE OF DISSOLUTION OF GROUP NOT APPLICABLE ITEM 10. CERTIFICATION BY SIGNING BELOW I CERTIFY THAT, TO THE BEST OF MY KNOWLEDGE AND BELIEF, THE SECURITIES REFERRED TO ABOVE WERE ACQUIRED AND ARE HELD IN THE ORDINARY COURSE OF BUSINESS AND WERE NOT ACQUIRED AND ARE NOT HELD FOR THE PURPOSE OR WITH THE EFFECT OF CHANGING OR INFLUENCING THE CONTROL OF THE ISSUER OF THE SECURITIES AND WERE NOT ACQUIRED AND ARE NOT HELD IN CONNECTION WITH OR AS A PARTICIPANT IN ANY TRANSACTION HAVING THAT PURPOSE OR EFFECT. SIGNATURES AFTER REASONABLE INQUIRY AND TO THE BEST OF HIS KNOWLEDGE AND BELIEF, EACH OF THE UNDERSIGNED CERTIFIES THAT THE INFORMATION SET FORTH IN THIS STATEMENT IS TRUE, COMPLETE AND CORRECT. 12 FEBRUARY 2010 STATE STREET CORPORATION /s/ JAMES J. MALERBA EXECUTIVE VICE PRESIDENT, CORPORATE CONTROLLER 12 FEBRUARY 2010 STATE STREET BANK AND TRUST COMPANY /s/ CUAN COULTER SENIOR VICE PRESIDENT CUSIP NO. 723484101 13G PAGE 7 OF 8 PAGES EXHIBIT 1 THE FOLLOWING TABLE LISTS THE IDENTITY AND ITEM 3 CLASSIFICATION OF EACH SUBSIDIARY OF STATE STREET CORPORATION, THE PARENT HOLDING COMPANY, THAT BENEFICIALLY OWNS THE ISSUER'S COMMON STOCK. PLEASE REFER TO ITEM 3 OF THE ATTACHED SCHEDULE 13G FOR A DESCRIPTION OF EACH OF THE TWO-LETTER SYMBOLS REPRESENTING THE ITEM 3 CLASSIFICATION BELOW. SUBSIDIARY ITEM 3 CLASSIFICATION STATE STREET BANK AND TRUST COMPANY BK SSGA FUNDS MANAGEMENT, INC IA STATE STREET GLOBAL ADVISORS LIMITED, LONDON IA STATE STREET GLOBAL ADVISORS LTD MONTREAL IA STATE STREET GLOBAL ADVISORS FRANCE S.A. IA STATE STREET GLOBAL ADVISORS AUSTRALIA, SYDNEY IA STATE STREET GLOBAL ADVISORS JAPAN CO., LTD., TOKYO IA STATE STREET GLOBAL ADVISORS ASIA LIMITED, HONG KONG IA STATE STREET GLOBAL ADVISORS GBMH, MUNICH IA NOTE: ALL OF THE LEGAL ENTITIES ABOVE ARE DIRECT OR INDIRECT SUBSIDIARIES OF STATE STREET CORPORTION. BENEFICIAL OWNERSHIP FOR STATE STREET BANK AND TRUST COMPANY IS REPORTED ON ITS OWN REPORTING PERSON COVER PAGE BECAUSE IT BENEFICIALLY OWNS MORE THAT FIVE PERCENT OF THE ISSUER'S COMMON STOCK. DO NOT ADD THE SHARES OR PERCENT OF CLASS REPORTED ON EACH REPORTING PERSON'S COVER PAGE OF THE ATTACHED SCHEDULE 13G TO DETERMINE THE TOTAL PERCENT OF CLASS BENEFICAILLY OWNED BY STATE STREET CORPORATION, AS THAT WILL RESULT IN DOUBLE COUNTING OF CERTAIN SHARES. CUSIP NO. 723484101 13G PAGE 8 OF 8 PAGES JOINT FILING AGREEMENT IN ACCORDANCE WITH RULE 13D-1(K)(1) UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED (THE EXCHANGE ACT), EACH UNDERSIGNED ENTITY (EACH A COMPANY)HEREBY AGREES TO ANY AND ALL JOINT FILINGS REQUIRED TO BE MADE ON THE COMPANY'S BEHALF ON SCHEDULE 13G (INCLUDING AMENDMENTS THERETO) UNDER THE EXCHANGE ACT, WITH RESPECT TO SECURITIES WHICH MAY BE DEEMED TO BE BENEFICIALLY OWNED BY THE COMPANY UNDER THE EXCHANGE ACT, AND THAT THIS AGREEMENT BE INCLUDED AS AN EXHIBIT TO ANY SUCH JOINT FILING. THIS AGREEMENT MAY BE EXECUTED IN ANY NUMBER OF COUNTERPARTS ALL OF WHICH TAKEN TOGETHER SHALL CONSTITUTE ONE AND THE SAME INSTRUMENT. IN WITNESS WHEREOF, EACH COMPANY HEREBY EXECUTES THIS AGREEMENT EFFECTIVE AS OF THE DATE SET FORTH BELOW. 12 FEBRUARY 2010 STATE STREET CORPORATION /s/ JAMES J. MALERBA EXECUTIVE VICE PRESIDENT, CORPORATE CONTROLLER 12 FEBRUARY 2010 STATE STREET BANK AND TRUST COMPANY /s/ CUAN COULTER SENIOR VICE PRESIDENT