EXHIBIT 5.1

                                                June 30, 1997



Schering-Plough Corporation
One Giralda Farms
Madison, NJ  07940-1000

RE:   Schering-Plough Corporation
      Registration Statement on Form S-3

Gentlemen:

     As Secretary of Schering-Plough Corporation, a New 
Jersey corporation (the "Corporation"), I have examined the 
Certificate of Incorporation and Bylaws of the Corporation as 
well as such other documents and proceedings as I have 
considered necessary for the purposes of this opinion.  I 
have also examined and am familiar with the Corporation's 
Registration Statement on Form S-3 (the "Registration 
Statement") as filed with the Securities and Exchange 
Commission under the Securities Act of 1933, relating to 
5,000,000 shares of the Corporation's Common Shares, par 
value $1.00 per share (the "Common Shares") which may be 
offered or sold to immediate family members of certain 
participants in the Corporation's 1997 Stock Incentive Plan 
(the "Plan"), pursuant to nonqualified stock options (the 
"Stock Options") granted to such participants under the Plan, 
some or all of which may be transferred by participants to 
immediate family members in accordance with the Plan and the 
grant documents specifying the terms and conditions of such 
Stock Options.

     Based upon the foregoing, and having regard to legal 
considerations which I deem relevant, I am of the opinion 
that the Common Shares have been duly authorized by the 
Corporation and, when (a) issued and delivered by the 
Corporation in accordance with the terms of the Plan and (b) 
paid for in full in accordance with the terms of the Plan, 
the Common Shares will be legally issued, fully paid and non-
assessable.

     This opinion is limited to the general corporation laws 
of the State of New Jersey and the federal law of the United 
States, and I do not express any opinion herein concerning 
any other law.  This opinion is intended solely for the 
Corporation's use in connection with the registration of the 
Common Shares and may not be relied upon for any other 
purpose or by any other person.  This opinion may not be 
quoted in whole or in part or otherwise referred to or 
furnished to any other person except in response to a valid 
subpoena.  This opinion is limited to the matters expressly 
stated herein, and no opinion is implied or may be inferred 
beyond the matters expressly stated herein.  This opinion is 
rendered as of the date hereof, and I assume no obligation to 
update or supplement such opinion to reflect any facts or 
circumstances that may hereafter come to my attention or any 
changes in facts or law that may hereafter occur.  I hereby 
consent to the inclusion of this opinion letter as an exhibit 
to the Registration Statement.

                                       Very truly yours,

                                       /s/ William J. Silbey


                                       William J. Silbey
                                       Secretary