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
                               -------------

      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.

      McKesson and HBO & Company ("HBOC"), a leading healthcare information
company, have signed a definitive merger agreement for McKesson to acquire
HBOC. Under the terms of the merger agreement, stockholders of HBOC would
receive a fixed exchange ratio of 0.37 shares of McKesson common stock for
each share of HBOC common stock in a tax-free exchange. The merger of the
two companies, which is subject to regulatory approval, McKesson and HBOC
shareholder approval and other customary conditions, would be accounted for
as a pooling of interests and is anticipated to close in the first quarter
of 1999. The new company would be named McKesson HBOC, and the corporate
headquarters of McKesson HBOC would be located in San Francisco,
California.

      Upon completion of the merger, Charles W. McCall, currently president
and chief executive officer of HBOC, would become chairman of McKesson
HBOC's board of directors, and Mark A. Pulido, currently president and
chief executive officer of McKesson, would become president and chief
executive officer of McKesson HBOC. Also upon completion of the merger,
McKesson HBOC's board of directors would consist of ten members, which
would include five members from the current McKesson board and five from
the current HBOC board.

                                                    (continued on next page)

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 29, 1998.



      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 (i) by the
deletion of items 20, 65 and 77 of that table and the substitution therefor
of items 20, 65 and 77 below, and (ii) by the addition of item 91 to that
table as follows:



                              Convertible Preferred                               Convertible Preferred
                              Securities Owned                                    Securities Owned
                              Prior to Offering         Number of                 After Offering
                              ---------------------     Convertible Preferred     ---------------------
"Selling Holder               Number        Percent     Securities Offered        Number        Percent
- ---------------               ------        ------      ---------------------     ------        -------
                                                                                   
20. Goldman, Sachs & Co.      163,600       4.09%             59,650              103,950       2.60%

65. Salomon Smith Barney
    Inc.                       55,000       1.38%             55,000                    0       0.00%

77. Federated Equity
    Income Fund               167,700       4.19%            147,500               20,200       0.51%

91. SoundShore Holdings
    Ltd.                      102,205       2.56%            102,205                    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)".