EXHIBIT 5.1

July 20, 1995

Nellcor Incorporated
4280 Hacienda Drive
Pleasanton, CA 94588

       Re:  Nellcor Incorporated:
            11,860,150 Shares of Common Stock

Ladies and Gentlemen:

    At  your request,  we have examined  the Registration Statement  on Form S-4
filed by you with the  Securities and Exchange Commission  on July 20, 1995,  in
connection  with the registration under the  Securities Act of 1933, as amended,
of 11,860,150 shares of  your Common Stock, par  value of $0.001 (the  "Stock").
The  Stock  is  to  be  issued to  the  former  stockholders  of Puritan-Bennett
Corporation, a  Delaware corporation  ("P-B"),  pursuant to  the terms  of  that
certain  Agreement and Plan of Merger, dated as  of May 21, 1995, as amended, by
and between  you,  Puma Merger  Corporation,  a Delaware  corporation  and  your
wholly-owned subsidiary, and P-B.

    In  connection with this opinion, we  have examined all proceedings taken by
you relating to the issuance and sale of up to 11,860,150 shares of the Stock.

    It is our opinion that the up to 11,860,150 shares of the Stock being issued
and sold  by  you, when  issued  and  sold in  the  manner referred  to  in  the
Registration  Statement, will  be legally  and validly  issued, fully  paid, and
nonassessable.

    We consent to  the use of  this opinion  as an exhibit  to the  Registration
Statement  and  further consent  to  all references  to  us in  the Registration
Statement, the Proxy  Statement/Prospectus constituting a  part thereof and  any
amendments thereto.

                                          Very truly yours,

   
                                          /s/ MORRISON & FOERSTER
    

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                                          Morrison & Foerster