PROSPECTUS SUPPLEMENT 
 (TO PROSPECTUS DATED JUNE 18, 1997) 
  
                4,000,000 TRUST CONVERTIBLE PREFERRED SECURITIES 
                            MCKESSON FINANCING TRUST
                  5% TRUST CONVERTIBLE PREFERRED SECURITIES 
          (LIQUIDATION AMOUNT $50 PER CONVERTIBLE PREFERRED SECURITY) 
                   GUARANTEED TO THE EXTENT SET FORTH HEREIN BY, 
                              MCKESSON CORPORATION

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      This Prospectus Supplement supplements and amends the Prospectus dated
 June 18, 1997 (the "Prospectus") relating to the 5% Trust Convertible
 Preferred Securities (the "Convertible Preferred Securities"), which
 represent preferred undivided beneficial interests in the assets of
 McKesson Financing Trust, a statutory business trust formed under the laws
 of the State of Delaware, and the shares of common stock, par value $.01
 per share, of McKesson Corporation, a Delaware corporation ("McKesson"),
 issuable upon conversion of the Convertible Preferred Securities. 
  
      The table on pages 56 through 58 of the Prospectus, which sets forth
 information with respect to the Selling Holders (as defined in the
 Prospectus) and the respective amounts of Convertible Preferred Securities
 beneficially owned by each Selling Holder that may be offered pursuant to
 the Prospectus (as supplemented and amended), is hereby amended by the
 addition  of item 90 as follows: 



  
                                 Convertible Preferred
                                 Securities Owned          Number of                Convertible Preferred
                                 Prior to Offering         Convertible Preferred    Securities Owned
                                                           Securities Offered       After Offering
   
"Selling Holder                  Number      Percent                                Number      Percent
 
                                                                                     
90. Prudential Securities Inc.   10,000       0.25%         10,000                    0           0.00%


 
   The Prospectus, together with this Prospectus Supplement, constitutes
 the prospectus required to be delivered by Section 5(b) of the Securities
 Act of 1933, as amended, with respect to offers and sales of the
 Convertible Preferred Securities and McKesson Common Stock issuable upon
 conversion of the Convertible Preferred Securities.  All references in the
 Prospectus to "this Prospectus" are hereby amended to read "this Prospectus
 (as supplemented and amended)". 
  
 PROSPECTIVE INVESTORS SHOULD CAREFULLY CONSIDER MATTERS DISCUSSED UNDER THE
 CAPTION "RISK FACTORS" BEGINNING ON PAGE 6 OF THE PROSPECTUS. 
  
 THESE SECURITIES HAVE NOT BEEN APPROVED OR DISAPPROVED BY THE SECURITIES
 AND EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION NOR HAS THE
 SECURITIES AND EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION
 PASSED UPON THE ACCURACY OR ADEQUACY OF THIS PROSPECTUS.  ANY
 REPRESENTATION TO THE CONTRARY IS A CRIMINAL OFFENSE. 
  
 The date of this Prospectus Supplement is October 12, 1998.