ARIZONA PUBLIC SERVICE COMPANY

                                   Securities


                             UNDERWRITING AGREEMENT
                             ----------------------


Credit Suisse First Boston Corporation                          January 13, 1998
PaineWebber Incorporated


Dear Sir or Madam:

                  1.  Introduction.  Arizona Public Service Company,  an Arizona
corporation (the "Company"),  proposes to issue and sell from time to time up to
$150,000,000 in aggregate principal amount of its unsecured debentures, notes or
other  evidences  of  indebtedness  (the  "Securities")   registered  under  the
registration  statements  referred to in Section 2(a).  The  Securities  will be
issued under the  Indenture,  dated as of January 15, 1998,  between the Company
and The Chase Manhattan Bank, as Trustee, (the "Original Indenture"), as amended
and supplemented by one or more Supplemental  Indentures between the Company and
the Trustee  (each,  a  "Supplemental  Indenture")  (the  Original  Indenture as
amended  and  supplemented  by  such  Supplemental  Indentures  being  sometimes
hereinafter  referred to as the  "Indenture").  The Securities will be issued in
one or more  series,  which  series may vary as to interest  rates,  maturities,
redemption provisions,  selling prices, and other terms, with all such terms for
any  particular  issue of the Securities  being  determined at the time of sale.
Particular issues of the Securities may be sold from time to time to one or more
of the firms to whom this Agreement is addressed,  and to such other  purchasers
as the Company shall  designate and as shall agree in writing to comply with the
terms and conditions of this Agreement,  for resale in accordance with the terms
of offering  determined at the time of sale. The Securities involved in any such
offering are hereinafter referred to as the "Purchased Securities," the party or
parties  that agree to  purchase  the same are  hereinafter  referred  to as the
"Underwriters"  of  such  Purchased   Securities,   and  the  representative  or
representatives  of the  Underwriters,  if any,  specified in a Terms  Agreement
referred to in Section 3 are hereinafter referred to as the "Representatives."

                  2.   Representations   and  Warranties  of  the  Company.   In
connection  with  each  offering  of  the  Purchased  Securities,   the  Company
represents and warrants to, and agrees with, the Underwriters that:

                  (a) A  registration  statement  (No.  333-15379)  relating  to
         $25,000,000 of the Securities,  the Company's first mortgage bonds (the
         "Bonds"),  or the  Company's  senior notes (the  "Senior  Notes") and a
         registration  statement (No. 333-27551) relating to $125,000,000 of the
         Securities,  the  Bonds  or the  Senior  Notes  (including  a  combined
         prospectus  relating to up to $150,000,000 of the Securities,  Bonds or
         Senior Notes) were filed with the  Securities  and Exchange  Commission
         (the  "Commission")  and  have  become  effective.   Such  registration
         statements,  as each is  amended  at the  time of the  Terms  Agreement
         referred  to in Section 3 

         relating to the Purchased  Securities,  are hereinafter  referred to as
         the  "First  Registration   Statement"  and  the  "Second  Registration
         Statement,"  respectively,   and,  together  with  any  related  462(b)
         registration  statement or amendment thereto,  are hereinafter referred
         to collectively as the  "Registration  Statements" and such prospectus,
         as  supplemented  as  contemplated by Section 3 to reflect the terms of
         the Purchased  Securities and terms of offering thereof,  including all
         material  incorporated by reference therein, is hereinafter referred to
         as the "Prospectus."

                  (b) Each part of the Registration  Statements  relating to the
         Securities, when such part became effective,  conformed in all material
         respects to the requirements of the Securities Act of 1933 (the "Act"),
         the Trust  Indenture  Act of 1939 (the "Trust  Indenture  Act") and the
         rules and regulations  (the "Rules and  Regulations") of the Commission
         and did not include any untrue  statement of a material fact or omit to
         state any material fact  required to be stated  therein or necessary to
         make the  statements  therein not  misleading,  and on the date of each
         Prospectus  Supplement  referred  to in  Section  3,  the  Registration
         Statements and the Prospectus will conform in all material  respects to
         the  requirements of the Act, the Trust Indenture Act and the Rules and
         Regulations,  and at such date none of such  documents will include any
         untrue  statement of a material fact or omit to state any material fact
         required  to be stated  therein  or  necessary  to make the  statements
         therein not misleading;  provided, however, that the foregoing does not
         apply to (a) statements in or omissions  from any such documents  based
         upon written  information  furnished to the Company by any  Underwriter
         specifically  for use  therein  or (b)  that  part of the  Registration
         Statements   that  consists  of  the  Statement  of   Eligibility   and
         Qualification  (Form  T-1) under the Trust  Indenture  Act of The Chase
         Manhattan Bank, as Trustee under the Indenture.

                  (c) An order of the Arizona Corporation  Commission shall have
         been granted authorizing the execution and delivery of the Supplemental
         Indenture  relating to the  Purchased  Securities  and the issuance and
         sale of the Purchased Securities on the terms and conditions herein and
         in the  Prospectus  and the Terms  Agreement  referred  to in Section 3
         relating to the Purchased Securities, and the approval or consent of no
         other  public body or  authority  is  necessary  to the  execution  and
         delivery of such Supplemental Indenture or the validity of the issuance
         and sale of the Purchased  Securities,  except as may be required under
         state securities or blue sky laws.

                  (d) The Company holds such valid  franchises,  certificates of
         convenience and necessity,  licenses, and permits as are necessary with
         respect to the  maintenance  and operation of its property and business
         as now  conducted,  except that (A) the Company from time to time makes
         minor  extensions of its system prior to the time a related  franchise,
         certificate,  license,  or  permit is  procured,  (B) from time to time
         communities already being served by the Company become incorporated and
         considerable  time may  elapse  before a  franchise  is  procured,  (C)
         certain franchises may have expired prior to the renegotiation thereof,
         (D) the  Company may not have  obtained  certain  permits or  variances
         relating to the environmental requirements described in any of its Form
         10-K  Report,  its Form  10-Q  Reports,  and/or  its  Form 8-K  Reports
         incorporated by reference in the Registration  Statements,  (E) certain
         minor defects and exceptions may exist which,  individually  and in the
         aggregate, are not deemed material, and (F) 
                                        2

         the Company does not make any representation regarding the geographical
         scope of any  franchise,  certificate,  license,  or permit that is not
         specific as to its geographical scope.

                  3. Purchase and Offering.  The obligation of the  Underwriters
to purchase, and the obligation of the Company to sell, the Purchased Securities
will be  evidenced  by an exchange of facsimile  transmission  or other  written
communications  (the "Terms  Agreement")  at the time the Company  determines to
sell  the  Purchased   Securities.   The  Terms   Agreement  shall  specify  (by
incorporation  by  reference  or  otherwise)  the party or parties  that will be
Underwriters,  the principal  amount to be purchased by each, the purchase price
to be paid by the  Underwriters,  any  compensation or commissions to be paid to
Underwriters,  the offering price, and the terms of the Purchased Securities not
already  specified in the  Indenture,  including,  but not limited to,  interest
rates, maturity,  redemption provisions, and sinking fund requirements,  if any.
The Terms  Agreement  shall also  specify  (by  incorporation  by  reference  or
otherwise) the time and date of delivery and payment (the "Closing  Date"),  the
place of delivery  and  payment,  and any details of the terms of offering  that
should be reflected in the prospectus supplement relating to the offering of the
Purchased  Securities (the "Prospectus  Supplement").  It is understood that the
Underwriters  will offer the Purchased  Securities  for sale as set forth in the
Prospectus.  The  obligations  of the  Underwriters  to purchase  the  Purchased
Securities shall be several and not joint.  Except as may otherwise be set forth
in the Terms Agreement,  the Purchased Securities will be in definitive form and
in such  denominations  and  registered  in such names as the  Underwriters  may
request.

                  4. Covenants of the Company.  In connection with each offering
of  Purchased  Securities,  the  Company  covenants  and agrees with the several
Underwriters that:

                  (a)  The  Company   will  advise  the   Underwriters   or  the
         Representatives  promptly of any proposed  amendment or supplementation
         of the First Registration Statement, the Second Registration Statement,
         or the Prospectus. The Company will also advise the Underwriters or the
         Representatives  of the institution by the Commission of any stop order
         proceedings in respect of the First Registration Statement,  the Second
         Registration  Statement,  or of any part thereof, and will use its best
         efforts to prevent the issuance of any such stop order and to obtain as
         soon as possible its lifting, if issued.

                  (b)  If,  at  any  time  when  a  prospectus  relating  to the
         Purchased  Securities  is required to be  delivered  under the Act, any
         event  occurs as a result of which the  Prospectus  as then  amended or
         supplemented  would include an untrue  statement of a material fact, or
         omit to state  any  material  fact  necessary  to make  the  statements
         therein,  in the light of the circumstances under which they were made,
         not  misleading,  or if  it is  necessary  at  any  time  to  amend  or
         supplement the First Registration  Statement,  the Second  Registration
         Statement,  or the  Prospectus  to  comply  with the Act,  the  Company
         promptly  will  prepare and file with the  Commission  an  amendment or
         supplement that will correct such statement or omission or an amendment
         that will effect such compliance.

                  (c) As soon as  practicable,  but not  later  than 18  months,
         after  the  date  of the  Terms  Agreement  relating  to the  Purchased
         Securities,  the Company will make generally  available to its security
         holders an earning  statement or statements (which need not be audited)
                                       3

         covering a period of at least 12 months  beginning  after the effective
         date of the Second  Registration  Statement  (as defined in Rule 158(c)
         under the Act),  which will satisfy the  provisions of Section 11(a) of
         the Act and the rules and regulations thereunder.

                  (d)  The  Company  will  furnish  to the  Underwriters  or the
         Representatives such copies of the Registration  Statements  (including
         one copy of the Second Registration  Statement for each Representative,
         or for each  Underwriter if there are no  Representatives,  and for the
         counsel  for  the  Underwriters,  which  is  signed  and  includes  all
         exhibits),  any  related  preliminary  prospectus  supplements  and the
         Prospectus,  including all amendments or supplements to such documents,
         as may be reasonably requested.

                  (e) The Company will arrange or cooperate in arrangements  for
         the  qualification  of  the  Purchased  Securities  for  sale  and  the
         determination  of their  eligibility  for investment  under the laws of
         such jurisdictions as the Underwriters or the Representatives designate
         and will continue such qualifications in effect so long as required for
         the distribution of the Purchased Securities, provided that the Company
         shall not be required to qualify as a foreign corporation in any State,
         to consent to service of process in any State  other than with  respect
         to  claims  arising  out of  the  offering  or  sale  of the  Purchased
         Securities,  or to meet  other  requirements  deemed by it to be unduly
         burdensome.

                  (f)  During  the  period of five  years  after the date of the
         Terms Agreement relating to the Purchased Securities,  the Company will
         furnish to the  Underwriters or the  Representatives  thereunder,  and,
         upon  request,  each  of  the  other  Underwriters,   (i)  as  soon  as
         practicable  after the end of each  fiscal  year,  a balance  sheet and
         statements of income and retained earnings of the Company as at the end
         of and for  such  year,  all in  reasonable  detail  and  certified  by
         independent  public  accountants,  and (ii) (A) as soon as  practicable
         after the end of each  quarterly  fiscal  period  (except  for the last
         quarterly  fiscal  period of each  fiscal  year),  a balance  sheet and
         statement  of  income  of the  Company  as at the end of and  for  such
         period, all in reasonable detail and certified by a principal financial
         or accounting officer of the Company, (B) as soon as available,  a copy
         of each report of the Company mailed by the Company to  stockholders or
         filed  with the  Commission,  and (C) from  time to  time,  such  other
         information  concerning the Company as may reasonably be requested.  So
         long as the Company has active subsidiaries,  such financial statements
         will be on a  consolidated  basis to the  extent  the  accounts  of the
         Company and its subsidiaries are consolidated.

                  (g)  The  Company  will  pay  all  expenses  incident  to  the
         performance of its obligations under this Agreement, and will reimburse
         the Underwriters for any reasonable expenses (including reasonable fees
         and  disbursements of counsel)  incurred by them in connection with the
         qualification  of the  Purchased  Securities  with respect to which the
         Terms Agreement  relating to the Purchased  Securities has been entered
         for sale, and the  determination  of their  eligibility for investment,
         under  the laws of such  jurisdictions  as the  Representatives  or, if
         there  are no  Representatives,  the  Underwriters  designate,  and the
         printing of  memoranda  relating  thereto,  and for any fees charged by
         investment rating agencies for the rating of the Purchased Securities.
                                       4

                  (h) The  Company  will  not  offer  or sell  any  other of its
         Securities for a period beginning at the time of execution of the Terms
         Agreement  relating  to the  Purchased  Securities  and  ending  on the
         Closing Date relating  thereto without prior consent of the Underwriter
         or the Representatives.

                  5.  Conditions of the  Obligations  of the  Underwriters.  The
obligations of the Underwriters to purchase and pay for the Purchased Securities
will be subject to the accuracy of the  representations  and  warranties  on the
part of the  Company  herein,  to the  accuracy  of the  statements  of  Company
officers made  pursuant to the  provisions  hereof,  to the  performance  by the
Company of its obligations hereunder, and to the following additional conditions
precedent:

                  (a)  The  Underwriters  or  the  Representatives   shall  have
         received a letter  from  DELOITTE & TOUCHE  LLP,  dated the date of the
         Terms Agreement,  confirming that they are independent certified public
         accountants within the meaning of the Act and the applicable  published
         Rules and  Regulations  thereunder,  and  stating in effect that (i) in
         their  opinion the  financial  statements  and schedules of the Company
         audited  by them and  incorporated  by  reference  in the  Registration
         Statements  comply  as to  form  in  all  material  respects  with  the
         applicable  accounting  requirements of the Securities  Exchange Act of
         1934  (the  "1934  Act")  and  the  published   Rules  and  Regulations
         thereunder  and (ii) on the basis of a reading of the latest  available
         interim financial statements of the Company,  inquiries of officials of
         the Company responsible for financial and accounting matters, and other
         specified procedures,  nothing came to their attention that caused them
         to believe that (A) the unaudited financial statements  incorporated by
         reference,  if any, in the Registration  Statements do not comply as to
         form  in  all  material   respects  with  the   applicable   accounting
         requirements  of the 1934 Act and the published  Rules and  Regulations
         thereunder or are not stated on a basis  substantially  consistent with
         that of the audited financial  statements  incorporated by reference in
         the  Registration  Statements,  (B) at the  date  of  the  most  recent
         available  unaudited  financial  statements and at a specified date not
         more than five days prior to the date of this Agreement,  there was any
         increase in the amounts of common stock, redeemable preferred stock, or
         non-redeemable   preferred  stock  of  the  Company  or  any  increase,
         exceeding $10,000,000, in long-term debt of the Company or, at the date
         of the most recent available unaudited  financial  statements there was
         any decrease in net assets as compared  with amounts  shown in the most
         recent   financial   statements   incorporated   by  reference  in  the
         Registration  Statements,  or (C) for the twelve-month  period ended at
         the date of the most recent available  unaudited  financial  statements
         there  were  any   decreases,   exceeding  3%,  as  compared  with  the
         twelve-month  period  ended at the date of the  most  recent  financial
         statements incorporated by reference in the Registration Statements, in
         the amounts of total  revenues  or net income,  except in all cases for
         increases or decreases  which result from the declaration or payment of
         dividends, or which the Registration Statements (including any material
         incorporated by reference therein) disclose have occurred or may occur,
         or which are described in such letter.

                  (b) No stop order  suspending the  effectiveness  of the First
         Registration Statement,  the Second Registration Statement, or any part
         thereof  shall have been  issued and no  proceedings  for that  purpose
         shall have been  instituted  or, to the knowledge of the Company or the
         Underwriters, shall be contemplated by the Commission.
                                       5

                  (c)  Subsequent  to  the  execution  of  the  Terms  Agreement
         relating to the Purchased Securities, (i) there shall not have occurred
         any change,  or any development  involving a prospective  change, in or
         affecting particularly the business or properties of the Company or its
         subsidiaries  which,  in the  judgment of a majority in interest of the
         Underwriters under such Terms Agreement, including any Representatives,
         materially impairs the investment quality of the Purchased  Securities,
         (ii) there shall not have occurred a suspension or material  limitation
         in  trading in  securities  generally  on the New York Stock  Exchange,
         (iii) there shall not have occurred a general  moratorium on commercial
         banking  activities in New York declared by either  Federal or New York
         State  authorities,  (iv)  no  rating  of  any of  the  Company's  debt
         securities  shall have been lowered and there shall have been no public
         announcement  that  any  such  debt  securities  have  been  placed  on
         CreditWatch, Watchlist, or under any similar surveillance or review, in
         each case with negative implications,  by any recognized rating agency,
         and (v) there shall not have  occurred  any outbreak or  escalation  of
         major  hostilities  in  which  the  United  States  is  involved,   any
         declaration  of war by  Congress or any other  substantial  national or
         international  calamity or emergency  if, in the judgment of a majority
         in interest of the Underwriters  under such Terms Agreement,  including
         any  Representatives,  the  effect  of any such  outbreak,  escalation,
         declaration,  calamity or emergency makes it impractical or inadvisable
         to proceed with completion of the sale of and payment for the Purchased
         Securities.

                  (d)  The  Underwriters  or  the  Representatives   shall  have
         received an opinion of Snell & Wilmer L.L.P.,  counsel for the Company,
         dated the relevant Closing Date, to the effect that:

                           (i) The  Company  is a  corporation  duly  organized,
                  validly  existing,  and in good standing under the laws of the
                  State of Arizona and has full corporate power and authority to
                  carry on its business as presently conducted;  and the Company
                  is duly  qualified as a foreign  corporation to do business in
                  the  States of New  Mexico,  California,  Oregon,  Washington,
                  Wyoming and Montana,  the only other jurisdictions in which it
                  owns or leases substantial  properties or in which the conduct
                  of its business requires such qualification;

                           (ii)  The   Purchased   Securities   have  been  duly
                  authorized,  executed,  authenticated,  issued, and delivered,
                  constitute  valid  and  legally  binding  obligations  of  the
                  Company  entitled to the  benefits  provided by the  Indenture
                  (except as the same may be limited by (a)  general  principles
                  of  equity  or  by  bankruptcy,  insolvency,   reorganization,
                  arrangement, moratorium, or other laws or equitable principles
                  relating to or affecting the enforcement of creditors'  rights
                  generally  and (b) the  qualification  that  certain  waivers,
                  procedures,  remedies,  and other  provisions of the Purchased
                  Securities  and the  Indenture may be  unenforceable  under or
                  limited by the law of the State of Arizona;  however, such law
                  does not in such counsel's opinion  substantially  prevent the
                  practical   realization  of  the  benefits  intended  by  such
                  documents)  and  conform  to the  description  thereof  in the
                  Prospectus;
                                       6

                           (iii)  The  Indenture   has  been  duly   authorized,
                  executed,  and delivered,  has been duly  qualified  under the
                  Trust  Indenture  Act,  and  constitutes  a valid and  binding
                  instrument  enforceable in accordance with its terms except as
                  the same may be limited by (a) general principles of equity or
                  by  bankruptcy,   insolvency,   reorganization,   arrangement,
                  moratorium,  or other laws or equitable principles relating to
                  or affecting the  enforcement of creditors'  rights  generally
                  and (b) the  qualification  that certain waivers,  procedures,
                  remedies, and other provisions of the Purchased Securities and
                  the Indenture may be unenforceable under or limited by the law
                  of the State of  Arizona;  however,  such law does not in such
                  counsel's   opinion   substantially   prevent  the   practical
                  realization of the benefits intended by such documents;

                           (iv)  With  certain  exceptions,   a  public  service
                  corporation is required to obtain  certificates of convenience
                  and necessity from the Arizona  Corporation  Commission  under
                  A.R.S.  Section 40-281.A for construction of its lines, plant,
                  services,  or systems, or any extensions  thereof,  within the
                  State of Arizona, and to obtain franchises or similar consents
                  or permits from counties and incorporated municipalities under
                  A.R.S. Section 40-283.A for the construction,  operation,  and
                  maintenance of transmission lines within the State of Arizona;
                  to the best of such counsel's knowledge after due inquiry, the
                  Company   holds  such  valid   franchises,   certificates   of
                  convenience and necessity,  consents,  and permits pursuant to
                  such statutory provisions as are necessary with respect to the
                  maintenance  and operation of its property and business as now
                  conducted, except that (A) the Company from time to time makes
                  minor  extensions  of its  system  prior to the time a related
                  franchise,  certificate,  license, or permit is procured,  (B)
                  from  time to time  communities  already  being  served by the
                  Company become  incorporated and considerable  time may elapse
                  before a franchise is  procured,  (C) certain  franchises  may
                  have expired prior to the renegotiation  thereof,  (D) certain
                  minor defects and exceptions may exist which, individually and
                  in the  aggregate,  are not  deemed  material,  and  (E)  such
                  counsel need not be required to express any opinion  regarding
                  the geographical scope of any franchise, certificate, license,
                  or permit that is not specific as to its geographical scope;

                           (v) The issuance and sale of the Purchased Securities
                  on the terms and conditions set forth or  contemplated  herein
                  and in the Prospectus and the Terms Agreement  relating to the
                  Purchased  Securities  and the  execution  and delivery of the
                  Supplemental  Indenture  relating to the Purchased  Securities
                  have  been  duly   authorized   by  the  Arizona   Corporation
                  Commission,  said Commission had jurisdiction in the premises,
                  and no  further  approval,  authorization,  or  consent of any
                  other  public  board or body is  necessary  to the validity of
                  such  issuance and sale of such  Purchased  Securities  or the
                  execution and delivery of such Supplemental Indenture,  except
                  as may be required under 
                                       7

                  state  securities  or blue sky  laws,  as to which  laws  such
                  counsel shall not be required to express an opinion;

                           (vi) The First Registration  Statement and the Second
                  Registration  Statement have become  effective  under the Act,
                  and, to the best of the  knowledge  of such  counsel,  no stop
                  order suspending the  effectiveness of the First  Registration
                  Statement or the Second Registration Statement has been issued
                  and no  proceedings  for that purpose have been  instituted or
                  are pending or  contemplated  under the Act,  and each part of
                  the Registration  Statements relating to the Securities,  when
                  such part became effective, and the Prospectus, as of the date
                  of the Prospectus Supplement, and each amendment or supplement
                  thereto,  as of their  respective  effective  or issue  dates,
                  complied  as  to  form  in  all  material  respects  with  the
                  requirements  of the Act,  the Trust  Indenture  Act,  and the
                  published Rules and Regulations; such counsel has no reason to
                  believe  that any part of the  Registration  Statements,  when
                  such part became effective, or the Prospectus,  as of the date
                  of the  Prospectus  Supplement,  or as of the Closing Date, or
                  any amendment or supplement  thereto,  as of their  respective
                  effective or issue dates, or as of the Closing Date, contained
                  any untrue  statement  of a material  fact or omitted to state
                  any material fact  required to be stated  therein or necessary
                  to  make  the   statements   therein   not   misleading;   the
                  descriptions in the Registration  Statements and Prospectus of
                  statutes,  legal and  governmental  proceedings and contracts,
                  and other  documents  are  accurate  and  fairly  present  the
                  information  required to be shown; and to the actual knowledge
                  of  those  persons  in the  lawyer  group  described  in  such
                  opinion,  there  are  no  legal  or  governmental  proceedings
                  required  to be  described  in the  Prospectus  that  are  not
                  described  as  required,  nor any  contracts or documents of a
                  character   required  to  be  described  in  the  Registration
                  Statements  or  Prospectus  or to be filed as  exhibits to the
                  Registration  Statements  that are not  described and filed as
                  required (it being  understood  that such counsel need express
                  no opinion as to the financial  statements or other  financial
                  data   contained  in  the   Registration   Statements  or  the
                  Prospectus); and

                           (vii) This  Agreement  and the Terms  Agreement  have
                  been duly authorized, executed, and delivered by the Company.

                  In giving such  opinion,  (a) Snell & Wilmer  L.L.P.  may rely
         solely upon  certificates of the Company as to any factual matters upon
         which any such  opinions  are based  and may rely upon the  opinion  of
         Keleher & McLeod,  P.A.,  referred to below, as to all matters governed
         by the laws of the  State of New  Mexico,  but the  opinion  of Snell &
         Wilmer L.L.P.  shall state that, though they are members of the Arizona
         Bar and do not hold  themselves out as experts on the laws of the State
         of New Mexico, they have made a study of the laws of such State insofar
         as such laws are involved in the  conclusions  stated in their opinion,
         and from such study it is their  opinion  that such laws  support  such
         conclusions and that, in their opinion,  the  Underwriters and they are
         justified  to such  extent in  relying  upon the  opinion  of Keleher &
         McLeod, P.A.; 
                                       8

         and (b) the lawyer  group  referred to in such  opinion will mean those
         lawyers in the offices of Snell & Wilmer L.L.P. who (i) have billed any
         time on the  particular  transaction  to which such opinion  relates or
         (ii)  have  billed  more than ten  hours to any  Company  matter in the
         twelve-month  period  preceding  the  date on  which  the  list of such
         lawyers was compiled for purposes of inquiry pursuant to such opinion.

                  (e)  The  Underwriters  or  the  Representatives   shall  have
         received an opinion of Keleher & McLeod,  P.A.,  New Mexico counsel for
         the Company, dated the Closing Date, to the effect that:

                           (i)  The  Company  is  duly  qualified  as a  foreign
                  corporation  to do  business  and is in good  standing  in the
                  State of New Mexico and has full corporate power and authority
                  to  engage  in the State of New  Mexico  in the  business  now
                  conducted by it therein; and

                           (ii) The  activities  of the  Company in the State of
                  New Mexico to date do not constitute it a "public  utility" as
                  that term is defined in the relevant  laws of the State of New
                  Mexico,  and  accordingly,  no public  utility  franchises  or
                  certificates  of convenience and necessity are necessary under
                  New Mexico law with respect to the  maintenance  and operation
                  of the Company's property and business as now conducted in the
                  State of New Mexico and no approval, authorization, or consent
                  of the New  Mexico  Public  Utility  Commission  or any  other
                  public  board or body of the State of New  Mexico is  required
                  for the issuance and sale of the  Purchased  Securities on the
                  terms and conditions herein and in the Prospectus set forth or
                  contemplated   or  for  the  execution  of  the   Supplemental
                  Indenture relating to the Purchased Securities,  except as may
                  be  required  under New Mexico  state  securities  or blue sky
                  laws,  as to which laws such counsel  shall not be required to
                  express an opinion.

         In giving such  opinion,  Keleher & McLeod,  P.A.  may rely solely upon
         certificates  of the Company as to any factual  matters  upon which any
         such opinions are based.

                  (f)  The  Underwriters  or  the  Representatives   shall  have
         received  from counsel for the  Underwriters  such opinion or opinions,
         dated the  Closing  Date,  with  respect  to the  incorporation  of the
         Company,  the validity of the Purchased  Securities,  the  Registration
         Statements, the Prospectus, and other related matters as may reasonably
         be required,  and the Company shall have furnished to such counsel such
         documents as they request for the purpose of enabling them to pass upon
         such matters.  In rendering  such opinion,  such counsel may rely as to
         the  incorporation of the Company and all other matters governed by the
         laws of the States of Arizona and New Mexico upon the opinions of Snell
         & Wilmer L.L.P. and Keleher & McLeod, P.A., referred to above.
                                       9

                  (g)  The  Underwriters  or  the  Representatives   shall  have
         received a  certificate  of the  President or any Vice  President and a
         principal  financial or  accounting  officer of the Company,  dated the
         Closing Date, in which such  officers,  to the best of their  knowledge
         after reasonable  investigation,  shall state that the  representations
         and  warranties of the Company in this  Agreement are true and correct,
         that the Company has complied  with all  agreements  and  satisfied all
         conditions  on its part to be performed or satisfied at or prior to the
         Closing Date, that no stop order  suspending the  effectiveness  of the
         First Registration  Statement or the Second Registration  Statement has
         been issued and no proceedings for that purpose have been instituted or
         are contemplated by the Commission, and that, subsequent to the date of
         the most recent financial statements in the Prospectus,  there has been
         no  material  adverse  change in the  financial  position or results of
         operations of the Company and its  subsidiaries  except as set forth or
         contemplated in the Prospectus or as described in such certificate.

                  (h)  The  Underwriters  or  the  Representatives   shall  have
         received a letter of  DELOITTE & TOUCHE LLP,  dated the  Closing  Date,
         which meets the requirements of subsection (a) of this Section,  except
         that the specified date referred to in such  subsection  will be a date
         not more than five days prior to the Closing  Date for the  purposes of
         this subsection.

                  The   Company   will   furnish   the   Underwriters   or   the
Representatives  with  such  conformed  copies of such  opinions,  certificates,
letters, and documents as may be reasonably requested.

                  6. Indemnification.

                  (a)  The  Company  will   indemnify  and  hold  harmless  each
         Underwriter  and each person,  if any, who  controls  such  Underwriter
         within the meaning of the Act against  any losses,  claims,  damages or
         liabilities,  joint or  several,  to  which  such  Underwriter  or such
         controlling  person may  become  subject,  under the Act or  otherwise,
         insofar as such losses, claims,  damages, or liabilities (or actions in
         respect thereof) arise out of or are based upon any untrue statement or
         alleged untrue  statement of any material fact contained in any part of
         the Registration Statements relating to the Securities,  when such part
         became effective,  any preliminary prospectus or preliminary prospectus
         supplement,  the Prospectus, or any amendment or supplement thereto, or
         arise out of or are based  upon the  omission  or alleged  omission  to
         state  therein  a  material  fact  required  to be  stated  therein  or
         necessary  to make the  statements  therein  not  misleading;  and will
         reimburse each  Underwriter  and each such  controlling  person for any
         legal or other expenses reasonably incurred by such Underwriter or such
         controlling  person in connection with  investigating  or defending any
         such loss, claim, damage, liability, or action; provided, however, that
         the Company  will not be liable in any such case to the extent that any
         such loss,  claim,  damage, or liability arises out of or is based upon
         an untrue  statement or alleged untrue statement or omission or alleged
         omission  made  in  any of  such  documents  in  reliance  upon  and in
         conformity  with  written  information  furnished to the Company by any
         Underwriter specifically for use therein. This indemnity agreement will
         be in addition to any liability which the Company may otherwise have.
                                       10

                  (b)  Each  Underwriter  will  severally   indemnify  and  hold
         harmless the Company,  each of its directors,  each of its officers who
         have signed the Registration  Statements,  and each person, if any, who
         controls the Company within the meaning of the Act, against any losses,
         claims,  damages,  or  liabilities  to which  the  Company  or any such
         director,  officer, or controlling person may become subject, under the
         Act  or  otherwise,   insofar  as  such  losses,  claims,  damages,  or
         liabilities  (or actions in respect  thereof) arise out of or are based
         upon any untrue  statement or alleged untrue  statement of any material
         fact contained in any part of the Registration  Statements  relating to
         the  Securities,  when  such part  became  effective,  any  preliminary
         prospectus or preliminary prospectus supplement, the Prospectus, or any
         amendment or supplement  thereto, or arise out of or are based upon the
         omission  or the  alleged  omission  to state  therein a material  fact
         required  to be stated  therein  or  necessary  to make the  statements
         therein not  misleading,  in each case to the  extent,  but only to the
         extent,  that such untrue  statement  or alleged  untrue  statement  or
         omission  or  alleged  omission  was  made  in  reliance  upon  and  in
         conformity  with written  information  furnished to the Company by such
         Underwriter  specifically for use therein; and will reimburse any legal
         or  other  expenses  reasonably  incurred  by the  Company  or any such
         director,   officer,   or   controlling   person  in  connection   with
         investigating or defending any such loss, claim, damage,  liability, or
         action.  This indemnity  agreement will be in addition to any liability
         which such Underwriter may otherwise have.

                  (c) Promptly after receipt by an indemnified  party under this
         Section of notice of the  commencement of any action,  such indemnified
         party  will,  if a claim in respect  thereof is to be made  against the
         indemnifying party under this Section, notify the indemnifying party of
         the   commencement   thereof;   but  the  omission  so  to  notify  the
         indemnifying  party will not relieve it from any liability  that it may
         have to any  indemnified  party  otherwise than under this Section.  In
         case any such action is brought against any indemnified  party,  and it
         notifies  the  indemnifying  party  of the  commencement  thereof,  the
         indemnifying party will be entitled to participate  therein and, to the
         extent  that it may wish,  jointly  with any other  indemnifying  party
         similarly  notified,  to  assume  the  defense  thereof,  with  counsel
         satisfactory  to such  indemnified  party (who shall not,  without  the
         consent  of the  indemnified  party,  be  counsel  to the  indemnifying
         party),   and  after  notice  from  the  indemnifying   party  to  such
         indemnified party of its election so to assume the defense thereof, the
         indemnifying  party will not be liable to such indemnified  party under
         this Section for any legal or other expenses  subsequently  incurred by
         such  indemnified  party in connection  with the defense  thereof other
         than reasonable costs of investigation. An indemnifying party shall not
         be liable for any settlement of a claim or action effected  without its
         written consent, which shall not be unreasonably withheld.

                  (d) If the  indemnification  provided  for in this  Section is
         unavailable or insufficient  to hold harmless an indemnified  party for
         any loss, claim, damage,  liability,  or action described in subsection
         (a) or (b) above, then each indemnifying  party shall contribute to the
         amount  paid or  payable by such  indemnified  party as a result of the
         losses, claims, damages or liabilities referred to in subsection (a) or
         (b) above on the  following  basis:  (1) if such loss,  claim,  damage,
         liability,  or action arises under  subsection  (a) above,  then (i) in
         such  proportion  as is  appropriate  to reflect the relative  benefits
         received  by the  Company on the one hand and the  Underwriters  on the
         other from the  offering of the  Securities  or (ii) if the  allocation
         provided by 
                                       11

         clause (i) above is not permitted by applicable law, in such proportion
         as is appropriate to reflect not only the relative benefits referred to
         in clause (i) above but also the  relative  fault of the Company on the
         one hand and the  Underwriters  on the  other  in  connection  with the
         statements or omissions which resulted in such losses,  claims, damages
         or liabilities as well as any other relevant equitable  considerations;
         and (2) if such loss, claim, damage,  liability, or action arises under
         subsection  (b) above,  then in such  proportion as is  appropriate  to
         reflect  the  relative  fault  of the  Company  on the one hand and the
         Underwriter on the other in connection with the statements or omissions
         which resulted in such losses,  claims,  damages or liabilities as well
         as any other  relevant  equitable  considerations.  For the purposes of
         clause (1) above, the relative  benefits received by the Company on the
         one hand and the Underwriters on the other shall be deemed to be in the
         same  proportion  as the total net proceeds  from the offering  (before
         deducting   expenses)  received  by  the  Company  bear  to  the  total
         underwriting  discounts and commissions  received by the  Underwriters.
         For the purposes of clauses (1) and (2) above, the relative fault shall
         be determined  by reference to, among other things,  whether the untrue
         or alleged  untrue  statement  of a material  fact or the  omission  or
         alleged  omission  to state a  material  fact  relates  to  information
         supplied by the Company or the Underwriters  and the parties'  relative
         intent, knowledge,  access to information and opportunity to correct or
         prevent  such  untrue  statement  or  omission.  The amount  paid by an
         indemnified  party  as a  result  of the  losses,  claims,  damages  or
         liabilities  referred to in the first  sentence of this  subsection (d)
         shall be  deemed to  include  any  legal or other  expenses  reasonably
         incurred by such indemnified party in connection with  investigating or
         defending  any action or claim which is the subject of this  subsection
         (d).   Notwithstanding  the  provisions  of  this  subsection  (d),  no
         Underwriter shall be required to contribute any amount in excess of the
         total  amount  by  which  the  total  price  at  which  the  Securities
         underwritten  by it and  distributed  to the public were offered to the
         public  exceeds the amount of any damages  which such  Underwriter  has
         otherwise  been  required  to pay by reason of such  untrue or  alleged
         untrue statement or omission or alleged  omission.  No person guilty of
         fraudulent  misrepresentation  (within the meaning of Section  11(f) of
         the Act) shall be entitled to contribution  from any person who was not
         guilty  of  such  fraudulent   misrepresentation.   The   Underwriters'
         obligations  in  this  subsection  (d) to  contribute  are  several  in
         proportion to their respective underwriting obligations and not joint.

                  7. Default of Underwriters. If any Underwriter or Underwriters
default in their obligations to purchase Purchased  Securities  pursuant to this
Agreement  and  the  Terms  Agreement  and the  principal  amount  of  Purchased
Securities that such defaulting Underwriter or Underwriters agreed but failed to
purchase  is ten  percent  (10%) or less of the  principal  amount of  Purchased
Securities  to which such  Terms  Agreement  relates,  the  Underwriters  or the
Representatives  may  make  arrangements  satisfactory  to the  Company  for the
purchase of such  Purchased  Securities by other  persons,  including any of the
Underwriters,  but if no such  arrangements  are  made by the  Closing  Date the
nondefaulting  Underwriters shall be obligated severally, in proportion to their
respective commitments hereunder and under such Terms Agreement, to purchase the
Purchased Securities that such defaulting Underwriter or Underwriters agreed but
failed to  purchase.  If any  Underwriter  or  Underwriters  so default  and the
aggregate  principal  amount of Purchased  Securities with respect to which such
default  or  defaults  occur  is  more  than  the  above-described   amount  and
arrangements  satisfactory to the remaining Underwriters and the Company for the
purchase  of such  Purchased  Securities  by other  persons  are not made within
thirty-six hours after such default, the Terms 
                                       12

Agreement will  terminate  without  liability on the part of any  non-defaulting
Underwriter  or the  Company,  except as  provided in Section 8. As used in this
Agreement,  the  term  "Underwriter"  includes  any  person  substituted  for an
Underwriter  under  this  Section.  Nothing  herein  will  relieve a  defaulting
Underwriter from liability for its default.

                  8. Survival of Certain  Representations  and Obligations.  The
respective  indemnities,  agreements,  representations,  warranties,  and  other
statements of the Company or its officers and of the  Underwriters  set forth in
or made  pursuant  to this  Agreement  will  remain  in full  force  and  effect
regardless of any investigation, or statement as to the results thereof, made by
or on  behalf of the  Underwriters  or the  Company  or any of its  officers  or
directors or any controlling  person,  and will survive  delivery of and payment
for the Purchased  Securities.  If any Terms Agreement is terminated pursuant to
Section 7, or if for any reason a purchase  pursuant to any Terms  Agreement  is
not  consummated,  the Company shall remain  responsible  for the expenses to be
paid or reimbursed by it pursuant to Section 4 and the respective obligations of
the Company and the Underwriters pursuant to Section 6 shall remain in effect.

                  9.  Notices.  All  communications  hereunder  relating  to any
offering  of  Purchased  Securities  will  be in  writing,  and,  if sent to the
Underwriters,  may be mailed,  delivered,  or  telecopied  and  confirmed to the
Representative  first named in the Terms  Agreement  relating to such  Purchased
Securities or the  Underwriters at their  addresses  furnished to the Company in
writing for the purpose of communications; provided, however, that any notice to
an Underwriter  pursuant to Section 6 will be mailed,  delivered,  or telecopied
and confirmed to each such  Underwriter at its own address.  All  communications
hereunder to the Company shall be mailed to the Company,  Attention:  Treasurer,
at P.O. Box 53999, Phoenix, Arizona 85072-3999,  or delivered, or telecopied and
confirmed to the Company at 400 North Fifth Street, Phoenix, Arizona 85004.

                  10.  Successors.  This  Agreement will inure to the benefit of
and be binding upon the parties hereto and the  Underwriter or  Underwriters  as
are  named in any  Terms  Agreement  and  their  respective  successors  and the
officers and directors and controlling  persons referred to in Section 6, and no
other person will have any right or obligation hereunder.

                  11.  Representation of Underwriters.  The Representatives,  if
any, may act for the  Underwriters  in  connection  with any offering to which a
Terms  Agreement may relate,  and any action under this  Agreement or such Terms
Agreement taken by the Representatives jointly or the Representative first named
in such Terms  Agreement in such capacity will be binding upon the  Underwriters
of Purchased Securities to which such Terms Agreement relates.

                  12.  Execution in  Counterpart.  This  Agreement and any Terms
Agreement  may be executed in one or more  counterparts,  each of which shall be
deemed to be an original,  but all such respective  counterparts  shall together
constitute a single instrument.
                                       13

                  If the foregoing is in accordance with your  understanding  of
our  agreement,  kindly  sign and return to us the  enclosed  duplicate  hereof,
whereupon  it will  become a  binding  agreement  between  the  Company  and the
Underwriters in accordance with its terms.

                                        Very truly yours,

                                        ARIZONA PUBLIC SERVICE COMPANY



                                        By        Michael V. Palmeri
                                          --------------------------------------
                                          Treasurer



The foregoing  Underwriting Agreement 
is hereby confirmed and accepted as 
of the date first above written.

CREDIT SUISSE FIRST BOSTON CORPORATION



By     Thomas R. Osborne
  ------------------------------------
  Director

PAINEWEBBER INCORPORATED



By     Peter Masco
  ------------------------------------
  Managing Director
                                       14

                                 TERMS AGREEMENT
                                 ---------------


                                                                January 13, 1998

Arizona Public Service Company
400 North Fifth Street
Phoenix, Arizona 85004

Attention:  Treasurer

Dear Sir:

                Arizona Public Service Company (the "Company")  hereby agrees to
sell to the several  Underwriters (the  "Underwriters")  listed in the Company's
Prospectus  Supplement  (the  "Prospectus  Supplement")  of even  date  herewith
relating to $100,000,000 in aggregate  principal  amount of its 6-1/4% Notes Due
2005  (the  "Purchased  Securities"),  and  the  Underwriters  hereby  agree  to
purchase,  severally  and not  jointly,  at a  purchase  price of 99.375% of the
principal  amount  thereof plus any accrued  interest  from the date of original
issuance,  the respective  principal  amounts of Purchased  Securities set forth
opposite the names of the Underwriters in the Prospectus Supplement. The sale of
the  Purchased  Securities  by the  Company  and  the  purchase  thereof  by the
Underwriters shall be made on the basis of the representations,  warranties, and
agreements   contained  in  the   Underwriting   Agreement  (the   "Underwriting
Agreement"),  dated January 13, 1998, relating to the issuance and sale of up to
$150,000,000  of the Company's  Securities  under the Company's  Indenture,  and
shall be  subject  to the terms and  conditions  set forth in such  Underwriting
Agreement.  The provisions of the Underwriting Agreement are incorporated herein
by  reference.  As  contemplated  by  Section 3 of the  Underwriting  Agreement,
certain  terms of the  Purchased  Securities  are  described  in the  Prospectus
Supplement.

                The  Underwriters  propose to offer the Purchased  Securities to
the  public  in the  manner  and  upon  the  terms  set  out  in the  Prospectus
Supplement.

                On January  16,  1998 the Company  will  deliver  the  Purchased
Securities to the  Underwriters in book-entry form through the facilities of the
Depository  Trust Company at the office of the Company,  400 North Fifth Street,
Phoenix,  Arizona  85004,  against  payment of the purchase price by transfer of
funds by Fed Wire from the  Underwriters  to the Company's  account at a bank in
Phoenix,  Arizona designated by the Company.  Such purchase price will be deemed
to have been received by the Company upon the Company's  receipt of the Fed Wire
reference number relating to such transfer of funds.  Closing shall occur at the
office of the Company,  400 North Fifth Street,  Phoenix,  Arizona, at 8:00 a.m.
Phoenix  time,  on  January  16,  1998,  or at such  other  time and date as the
Underwriters and the Company may agree upon in writing, such time and date being
referred to as the "Closing Date." All of the Purchased  Securities  referred to
in this  paragraph  shall be in global form and registered in the name of Cede &
Co. and deposited with the Depository Trust Company, as depositary.

TERMS AGREEMENT
Page 2

                If the  foregoing is  acceptable  to you,  please sign below and
transmit  evidence of such signing to Credit Suisse First Boston  Corporation at
your earliest  convenience.  At that point, the agreement  signified hereby will
constitute the Terms Agreement, as described in the Underwriting Agreement, with
respect to the $100,000,000 of Purchased Securities referred to herein.

                All capitalized terms herein,  not otherwise defined herein, are
used as defined in the Underwriting Agreement. This agreement may be executed in
one or more counterparts,  each of which shall be deemed to be an original,  but
all such respective counterparts shall together constitute a single instrument.


                                          Very truly yours,

                                          CREDIT SUISSE FIRST BOSTON CORPORATION
                                          PAINEWEBBER INCORPORATED

                                          By: CREDIT SUISSE FIRST BOSTON
                                              CORPORATION
                                              (As Representative of the
                                              Several Underwriters)



                                              By      Thomas R. Osborne
                                                --------------------------------
                                                Director



Confirmed and accepted as 
of the date first above written.

ARIZONA PUBLIC SERVICE COMPANY



By     Michael V. Palmeri
  ----------------------------
  Treasurer