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): September 21, 1999


                         ARIZONA PUBLIC SERVICE COMPANY
             ------------------------------------------------------
             (Exact name of registrant as specified in its charter)


          Arizona                        1-4473                86-0011170
- ----------------------------          -----------         ----------------------
(State or other jurisdiction          (Commission             (IRS Employer
      of incorporation)               File Number)        Identification Number)


400 North Fifth Street, P.O. Box 53999, Phoenix, Arizona          85004
- --------------------------------------------------------        ----------
       (Address of principal executive offices)                 (Zip Code)


                                 (602) 250-1000
              ----------------------------------------------------
              (Registrant's telephone number, including area code)


                                      NONE
          -------------------------------------------------------------
          (Former name or former address, if changed since last report)

ITEM 5. OTHER EVENTS

SETTLEMENT AGREEMENT

     As  previously  reported,  on August  26,  1999,  the  Arizona  Corporation
Commission  ("ACC")  Hearing  Officer  issued  a  recommended  decision  on  the
comprehensive  Settlement  Agreement between Arizona Public Service Company (the
"Company"  or  "we")  and  various  other  parties.   See  "Proposed  Settlement
Agreement"  in Item 5 of the Company's  Current  Report on Form 8-K dated August
26, 1999 (the "August 8-K"). On September 23, 1999, the ACC voted to approve the
Settlement  Agreement,  with some  modifications,  which will be effective  upon
signing of the written order by the Commissioners.

     The following  are the major  provisions of the  Settlement  Agreement,  as
approved:

     *    We will reduce rates for standard  offer  service for  customers  with
          loads less than 3 megawatts in a series of annual rate  reductions  of
          1.5% beginning July 1, 1999 through July 1, 2003, for a total of 7.5%.
          The first  reduction of  approximately  $24 million ($14 million after
          income  taxes)  includes  the July 1, 1999  retail  price  decrease of
          approximately $10.8 million annually ($6.5 million after income taxes)
          related to the 1996 regulatory agreement. For customers having loads 3
          megawatts or greater,  standard  offer rates will be reduced in annual
          increments that total 5% through 2002.

     *    Unbundled  rates being  charged by us for  competitive  direct  access
          service (for example,  distribution  services)  will become  effective
          upon the signing of the written order by the  Commissioners,  and will
          be  subject to annual  reductions,  that vary by rate  class,  through
          2003.

     *    There will be a moratorium  on retail rate changes for standard  offer
          and  unbundled  competitive  direct  access  rates until July 1, 2004,
          except for the price  reductions  described  above and  certain  other
          limited  circumstances.  Neither  the  ACC  nor  the  Company  will be
          prevented  from seeking or  authorizing  rate changes prior to July 1,
          2004 in the event of conditions or  circumstances  that  constitute an
          emergency,  such as an inability to finance on  reasonable  terms,  or
          material  changes in the Company's  cost of service for  ACC-regulated
          services  resulting  from  federal,   tribal,  state  or  local  laws,
          regulatory requirements, judicial decisions, actions or orders.

     *    We  will  be  permitted  to  defer  for  later  recovery  prudent  and
          reasonable costs of complying with the ACC electric competition rules,
          system  benefits  costs in excess of the  levels  included  in current
          rates,  and costs  associated  with our  "provider of last resort" and
          standard offer obligations for service after July 1, 2004. These costs
          are to be recovered through an adjustment clause or clauses commencing
          on July 1, 2004.

     *    Our  distribution  system  will be open  for  retail  access  upon the
          signing of the written order by the  Commissioners.  Customers will be
          eligible for retail  access in  accordance  with  the phase-in adopted

          by the ACC under the electric  competition rules (see "Retail Electric
          Competition Rules" below), with an additional 140 megawatts being made
          available to eligible  non-residential  customers.  Unless  subject to
          judicial or regulatory restraint, we will open our distribution system
          to retail access for all customers on January 1, 2001.

     *    We are currently recovering substantially all of our regulatory assets
          through July 1, 2004,  pursuant to the 1996 regulatory  agreement.  In
          addition,  the Settlement  Agreement states that we have  demonstrated
          that our allowable  stranded costs,  after mitigation and exclusive of
          regulatory  assets,  are at least $533 million net present  value.  We
          will not be allowed to recover $183  million net present  value of the
          above amounts. The Settlement Agreement provides that we will have the
          opportunity  to recover  $350  million  net  present  value  through a
          competitive transition charge (CTC) that will remain in effect through
          December   31,   2004,   at  which   time  it  will   terminate.   Any
          over/under-recovery will be credited/debited against the costs subject
          to recovery under the adjustment clause described above.

     *    We will form a separate corporate affiliate or affiliates and transfer
          thereto our generating  assets and competitive  services at book value
          as of the  date of  transfer,  which  transfer  shall  take  place  by
          December  31,  2002.  Sixty-seven  percent  of our  costs to  transfer
          generation  assets to an affiliate shall be allowed to be deferred for
          future collection.

     *    When the Settlement Agreement approved by the ACC is no longer subject
          to  judicial  review,  we will move to dismiss  all of our  litigation
          pending  against the ACC as of the date we entered into the Settlement
          Agreement.

Upon final ACC order,  we will  discontinue  the  application  of  Statement  of
Financial  Accounting  Standards No. 71,  "Accounting for the Effects of Certain
Types of Regulation," for our generation operations.  This means that regulatory
assets,  unless  reestablished  as recoverable  through  ongoing  regulated cash
flows,  are to be  eliminated  and the  generation  assets  must be  tested  for
impairment.  The  regulatory  disallowance,  which removes $234 million  pre-tax
($183 million net present  value) from ongoing  regulatory  cash flows,  will be
recorded as a net reduction of regulatory  assets.  This reduction ($140 million
after income  taxes) will be reported in the third  quarter as an  extraordinary
charge on the income statement. The regulatory assets to be recovered under this
Settlement Agreement will be amortized as follows:

                                   (Millions)
                                                          1/1 - 6/30
1999        2000       2001        2002        2003          2004         Total
- ----        ----       ----        ----        ----          ----         ------
$164        $158       $145        $115         $86           $18           $686

RETAIL ELECTRIC COMPETITION RULES

     As previously reported,  on August 26, 1999, the ACC Hearing Officer issued
a  recommended   decision  on  the  rules  that  provide  a  framework  for  the
introduction  of retail  electric  competition  in Arizona  (the  "Rules").  See
"Proposed  Retail  Electric  Competition  Rules" in Item 5 of the August 8-K. On
September 21, 1999, the ACC voted to approve the Rules,  which will be effective
upon signing of the written order by the Commissioners.

     The Rules approved by the ACC include the following major provisions:

     *    They apply to virtually all Arizona  electric  utilities  regulated by
          the ACC, including us.

     *    The  Rules  require  each  affected  utility,  including  us,  to make
          available  at least 20% of its 1995  system  retail  peak  demand  for
          competitive  generation  supply  beginning  when the ACC makes a final
          decision on each utility's  stranded costs and unbundled  rates (Final
          Decision  Date) or January 1, 2001,  whichever  is  earlier,  and 100%
          beginning January 1, 2001. Under the Settlement Agreement, the Company
          will provide retail access to customers  representing  the minimum 20%
          required by the ACC and an additional 140 megawatts of non-residential
          load as of July 1, 1999,  and to all  customers as of January 1, 2001,
          or such other dates as approved by the ACC.

     *    Subject to the 20%  requirement,  all  utility  customers  with single
          premise  loads  of one  megawatt  or  greater  will  be  eligible  for
          competitive  electric  services on the Final Decision Date,  which for
          the Company's customers will be the issuance of the final ACC order on
          the Settlement  Agreement.  Customers may aggregate loads to meet this
          one megawatt requirement.

     *    When effective,  residential customers will be phased in at 1 1/4% per
          quarter  calculated  beginning on January 1, 1999,  subject to the 20%
          requirement above.

     *    Electric  service  providers that get  Certificates of Convenience and
          Necessity  (CC&Ns) from the ACC can supply only competitive  services,
          including  electric  generation,  but not  electric  transmission  and
          distribution.

     *    Affected  utilities  must file ACC tariffs with  separate  pricing for
          electric services provided for noncompetitive services.

     *    The  ACC  shall  allow  a  reasonable   opportunity  for  recovery  of
          unmitigated stranded costs.

     *    Absent an ACC waiver,  prior to January 1, 2001, each affected utility
          (except certain electric  cooperatives)  must transfer all competitive
          generation assets and services either to an unaffiliated party or to a
          separate  corporate  affiliate.  Under the Settlement  Agreement,  the
          Company  received  a  waiver  to  allow  transfer  of its  competitive
          generation  assets and services to  affiliates  no later than December
          31, 2002.

                                   SIGNATURES

     Pursuant to the  requirements  of the Securities  Exchange Act of 1934, the
Company  has  duly  caused  this  report  to be  signed  on  its  behalf  by the
undersigned hereunto duly authorized.


                                        ARIZONA PUBLIC SERVICE COMPANY
                                                  (Registrant)


Dated: September 24, 1999               By: Nancy C. Loftin
                                            ------------------------------------
                                            Nancy C. Loftin
                                            Vice President and General Counsel