Exhibit 5.1

                                  June 27, 2001


Arizona Public Service Company
400 North 5th Street
Phoenix, Arizona  85004

Ladies and Gentlemen:

     Reference is made to (a) your proposed offering of up to $725,000,000 of
your securities (the "Securities"), as contemplated by the combined prospectus
contained in the Registration Statement (the "Registration Statement") on Form
S-3 to be filed by you on June 27, 2001, with the Securities and Exchange
Commission under the Securities Act of 1933, as amended (the "Act"), which
Securities include (i) $500,000,000 of first mortgage bonds, debt securities, or
any combination thereof, to be registered pursuant to the Registration
Statement; and (ii) $225,000,000 of first mortgage bonds, debt securities, or
any combination thereof, previously registered under Registration No. 333-94277;
and (b) any registration statement registering additional Securities pursuant to
Rule 462(b) of the Act that relates to the Registration Statement (the "Rule
462(b) Registration Statement").

     We have examined originals or copies, certified or otherwise identified to
our satisfaction, of such corporate records, agreements, and other instruments,
certificates, orders, opinions, correspondence with public officials,
certificates provided by your officers and representatives, and other documents
as we have deemed necessary or advisable for the purposes of rendering the
opinions set forth herein.

     Based on the foregoing, it is our opinion that after (i) the Registration
Statement, and the Rule 462(b) Registration Statement, if applicable, shall have
become effective, (ii) all required regulatory approvals have been obtained, and
(iii) you shall have entered into one or more underwriting or distribution
agreements with respect to the Securities then to be offered and the initial
public offering price for each of such Securities and the discounts therefrom
and commission therefor shall have been determined in accordance with such
underwriting or distribution agreements, pursuant to the authorization of your
Board of Directors and the applicable order of the Arizona Corporation
Commission, then, when (i) the Securities have been issued, sold, executed,
authenticated, and delivered, and (ii) the purchase price therefor has been paid
to you as contemplated in the Registration Statement and the Rule 462(b)
Registration Statement, if applicable (including the Exhibits thereto), and in
any relevant amendment thereto or in any Rule 424 supplement to the prospectus
contained in the Registration Statement; the Securities will be validly issued
and will constitute legal, valid, and binding obligations of you

Arizona Public Service Company
June 27, 2001
Page 2

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, or by equitable principles that limit the right to specific
performance or otherwise limit remedial action or the enforcement of any
security provided for the Securities, (b) the necessity for compliance with the
statutory procedural requirements governing the exercise of remedies by a
secured creditor, and (c) the qualification that certain waivers, procedures,
remedies, and other provisions of the Securities may be unenforceable under or
limited by the law of the State of Arizona; however, such law does not in our
opinion substantially prevent the practical realization of the benefits thereof.
In giving the above opinion, we have assumed that the law of the jurisdiction or
jurisdictions that govern the Securities is substantially the same as the law of
the State of Arizona.

     Consent is hereby given to the use of this opinion as part of the
Registration Statement and the Rule 462(b) Registration Statement, if
applicable, and to the use of our name wherever it appears in said Registration
Statement, the related prospectus, and the Rule 462(b) Registration Statement,
if applicable.


                                        Very truly yours,


                                        Snell & Wilmer