EXHIBIT 5.1




                              June 11, 1998


McKesson Corporation
McKesson Plaza
One Post Street
San Francisco, CA  94104

Ladies and Gentlemen:

          We have acted as special counsel to McKesson Corporation, a Delaware
corporation (the "Company"), in connection with the preparation of the
Registration Statement on Form S-4 No (such Registration Statement being
hereinafter referred to as the "Registration Statement") filed today by the
Company with the Securities and Exchange Commission (the "Commission") with
respect to the registration under the Securities Act of 1933, as amended (the
"Securities Act"), of 5,000,000 shares (the "Shares") of the Company's common
stock, $0.01 par value per share (and the associated rights to purchase and the
Series A Junior Participating Preferred Stock of the Company, collectively 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.

          In connection with this opinion, we have examined originals or copies,
certified or otherwise identified to our satisfaction, of (i) the Registration
Statement; (ii) a specimen certificate representing the Common Stock; (iii) the
Restated Certificate of Incorporation of the Company; (iv) the Restated By-Laws
of the Company; and (v)

 
McKesson Corporation
June 11, 1998
Page 2
              
certain resolutions of the Board of Directors of the Company relating to the
transactions contemplated by the Registration Statement and related matters (the
"Resolutions"). We have also examined originals or copies, certified or
otherwise identified to our satisfac tion, of such other 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 genuineness 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 or photostatic copies and the
authenticity of the originals of such latter documents. In making our
examination of documents executed by parties other than the Company, we have
assumed that such parties 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 opinion expressed herein which we did
not independently establish or verify, we have relied upon oral or written
statements and representations of officers and other representatives of the
Company and others.

          Members of our firm are admitted to the Bar of the State of
California, and we do not express any opinion as to the laws of any jurisdiction
other than the Delaware General Corporation Law.

          Based upon and subject to the foregoing, we are of the opinion that
when (i) the Shares are issued in accordance with the procedures set forth in
the Resolutions; (ii) the Registration Statement becomes effective; (iii) the
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 delivered against receipt of the consideration
therefore as contemplated by the Registration Statement and any prospectus
supplemental relating thereto, the issuance of the Shares will have been duly
authorized, and the Shares will be validly issued, fully paid and non-
assessable.

 
McKesson Corporation
June 11, 1998
Page 3
              
          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 do not thereby admit that we are included in the
category of persons whose consent is required under Section 7 of the Securities
Act or the rules and regulations of the Commission.  This opinion is expressed
as of the date hereof, and we disclaim any under  taking to advise you of any
subsequent changes in the facts stated or assumed herein or of any subsequent
changes in applicable law.


                         Very truly yours,



                         Skadden, Arps, Slate, Meagher &
                         Flom LLP