Exhibit 5.1


                              Snell & Wilmer L.L.P.
                               One Arizona Center
                           Phoenix, Arizona 85004-2202



November 29, 2001


Alliance Medical Corporation
10232 South 51st Street
Phoenix, AZ  85004

      Re:   Registration Statement on Form S-1 (File No. 333-13844)

Ladies and Gentlemen:

      We have acted as special counsel to Alliance Medical Corporation, a
Delaware corporation (the "Company"), in connection with the initial public
offering by the Company of up to 4,600,000 shares (the "Shares"), including
600,000 shares subject to an over-allotment option, of the Company's common
stock, par value $0.001 per share (the "Common Stock").

      This opinion is being furnished in accordance with the requirements of
Item 601(b)(5) of Regulation S-K under the Securities Act of 1933, as amended
(the "Act").

      In connection with this opinion, we have examined originals or copies,
certified or otherwise identified to our satisfaction, of (i) the Registration
Statement on Form S-1 (File No. 333-13844) as filed with the Securities and
Exchange Commission (the "Commission") on August 23, 2001; (ii) Amendment No. 1
to the Registration Statement as filed with the Commission on October 10, 2001;
(iii) Amendment No. 2 to the Registration Statement as filed with the Commission
on November 13, 2001; (iv) Amendment No. 3 to the Registration Statement as
filed with the Commission on the date hereof (such Registration Statement, as so
amended, being hereinafter referred to as the "Registration Statement"); (v) the
form of Underwriting Agreement (the "Underwriting Agreement") proposed to be
entered into by and among the Company, as issuer, and UBS Warburg LLC, RBC Dain
Rauscher Inc., and SG Cowen Securities Corporation, as representatives of the
several underwriters named therein (the "Underwriters"), filed as an exhibit to
the Registration Statement; (vi) a specimen certificate representing the Common
Stock; (vii) the Amended and Restated Certificate of the Company, as amended to
date and currently in effect; (viii) the Certificate of Amendment to the Amended
and Restated Certificate of Incorporation filed as Exhibit 3.1(b) to the
Registration Statement; (ix) the Amended and Restated By-Laws of the Company, as
amended to date and currently in effect; (x) certain resolutions of the Board of
Directors of the Company, relating to the issuance and sale of the Shares and
related matters; and (xi) certain resolutions of the stockholders of the Company
relating to the Company's Amended and Restated Certificate of Incorporation.

      We also have examined originals or copies, certified or otherwise
identified to our satisfaction, of such records of the Company and such
agreements, certificates of public officials, certificates of officers or other
representatives of the Company and others, and such other

Alliance Medical Corporation
November 29, 2001
Page 2

documents, certificates, and records as we have deemed necessary or appropriate,
as a basis for the opinion set forth herein.

      In our examination, we have assumed the legal capacity of all natural
persons, the genuiness of all signatures, the authenticity of all documents
submitted to us as originals, the conformity to original documents of all
documents submitted to us as certified, conformed, or photostatic copies, and
the authenticity of the originals of such latter documents. In making our
examination of executed documents, we have assumed that the parties thereto,
other than the Company, its directors and officers, had the power, corporate or
other, to enter into and perform all obligations thereunder and have also
assumed the due authorization by all requisite action, corporate or other, and
execution and delivery by such parties of such documents and the validity and
binding effect thereof on such parties. As to any facts material to the opinions
expressed herein that we have not independently established or verified, we have
relied upon statements and representations of officers and other representatives
of the Company and others.

      Members of our firm are admitted to the bar in the State of Arizona and we
do not express any opinion as to the laws of any jurisdiction other than the
corporate laws of the State of Delaware, and we do not express any opinion as to
the effect of any other laws on the opinion stated herein.

      Based upon and subject to the foregoing, we are of the opinion that, when
(a) the Registration Statement becomes effective under the Act; (b) the
Underwriting Agreement has been duly executed and delivered; and (c)
certificates representing the Shares in the form of the specimen certificate
examined by us have been manually signed by an authorized officer of the
transfer agent and registrar for the Common Stock and registered by such
transfer agent and registrar, and have been delivered to and paid for by the
Underwriters at a price per share not less than the per share par value of the
Common Stock as contemplated by the Underwriting Agreement, the Shares will be
validly issued, fully paid, and nonassessable.

      We hereby consent to the filing of this opinion with the Commission as an
exhibit to the Registration Statement. We also consent to the reference to our
firm under the caption "Legal Matters" in the Registration Statement. In giving
this consent, we are not admitting that we are included in the category of
persons whose consent is required under Section 7 of the Act or the rules and
regulations of the Commission.

                                            Very truly yours,

                                            SNELL & WILMER L.L.P.