EXHIBIT 23.1 CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS As independent public accountants, we hereby consent to the incorporation by reference in this Amendment No. 1 to the Registration Statement on Form S-4 of McKesson Corporation of our reports dated February 6, 1998 included or incorporated by reference in HBO & Company's Form 10-K for the year ended December 31, 1997 and to all references to our firm included in this registration statement. /s/ Arthur Andersen LLP ------------------------------------ ARTHUR ANDERSEN LLP Atlanta, Georgia November 25, 1998