EXHIBIT 99.4
 
PROXY

                             MCKESSON CORPORATION

                           Proxy for Special Meeting
                          1:00 P.M., February 9, 1998

       Solicited on Behalf of the Board of Directors of the Corporation

The undersigned, whose signature appears on the reverse side, hereby constitutes
and appoints Mark A. Pulido, Ivan D. Meyerson and Nancy A. Miller, and each of 
them, with full power of substitution, proxies to vote all stock of McKesson 
Corporation which the undersigned is entitled to vote at the Special Meeting of 
Stockholders to be held in the Franciscan Room at the Ana Hotel, 50 Third
Street, San Francisco, California, on February 9, 1998, and any adjournments
thereof, as specified upon the matters indicated on the reverse side, and in
their discretion upon any other matters that may properly come before said
meeting.

You are urged to specify your voting preference by marking the appropriate box, 
SEE REVERSE SIDE, but you need not mark any box if you wish to vote in 
accordance with the Board of Directors' recommendation. The above named proxies 
cannot vote your shares unless you sign and return this card.

                                                                ----------------
                                                                SEE REVERSE SIDE
                                                                ----------------



 
[X] Please mark your                                                  
    votes as in this 
    example

   This proxy when properly executed will be voted in the manner directed 
below.  If no direction is given, this proxy will be voted FOR the following 
proposal.
- -----------------------------------------------------------------------------
     The Board of Directors Recommends a Vote FOR the Following Proposal.
- -----------------------------------------------------------------------------

1. Approval of the issuance of shares of McKesson Corporation ("McKesson")
   common stock, par value $0.01 per share, in the merger of AmeriSource Health
   Corporation ("AmeriSource") with and into McKesson in accordance with the
   Agreement and Plan of Merger dated as of September 22, 1997, as amended, by
   and among McKesson, Patriot Acquisition Corp., a newly formed, wholly owned
   subsidiary of McKesson, and AmeriSource.

   FOR      AGAINST   ABSTAIN
  [   ]      [   ]     [   ]


   Signature             (Signature, if held jointly)           Date:      1998
            -------------                            -----------    ------

   Please sign exactly as name appears hereon. Joint owners should each sign.
   When signing as attorney, executor, administrator, trustee or guardian,
   please give full title as such.