EXHIBIT 8.1

July 18, 1995

Nellcor Incorporated
4280 Hacienda Drive
Pleasanton, CA 94588

    RE: NELLCOR INCORPORATED PROXY STATEMENT
       AND REGISTRATION STATEMENT ON FORM S-4

Ladies and Gentlemen:

    We  have acted  as counsel to  Nellcor Incorporated,  a Delaware corporation
("Nellcor")  and  Puma  Merger  Corporation,   a  Delaware  corporation  and   a
wholly-owned  subsidiary of Nellcor ("Sub") in connection with the Agreement and
Plan of Merger, dated as of May  21, 1995 (the "Merger Agreement"), as  amended,
by   and  among  Nellcor,  Sub   and  Puritan-Bennett  Corporation,  a  Delaware
corporation ("P-B").

    Pursuant to the  Merger Agreement,  Sub will merge  into and  with P-B  (the
"Merger").  As a result of the Merger, P-B will become a wholly-owned subsidiary
of Nellcor and  the former shareholders  of P-B will  receive shares of  Nellcor
common stock, all on the terms set forth in the Merger Agreement.

    The  Merger Agreement and certain proposed transactions incident thereto are
described in the Registration  Statement on Form S-4  filed by Nellcor with  the
Securities  and Exchange Commission (the "Registration Statement"). This opinion
is being rendered pursuant to the requirements  of Item 21(a) of Form S-4  under
the Securities Act of 1933, as amended.

    In  connection with this opinion, we have examined and are familiar with the
Merger Agreement, the Registration Statement, and such other presently  existing
documents,  records  and  matters  of  law  as  we  have  deemed  necessary  and
appropriate in connection with rendering this opinion.

    In rendering this opinion, we assume the following:

    1.  The authenticity of original  documents submitted to us, the  conformity
to original documents of all documents submitted to us as photostatic copies and
the  authenticity of the  originals of such  copies, and the  genuineness of all
signatures and the due execution and delivery of all documents.

    2.  The truth  and accuracy of  the representations, warranties,  statements
and  facts made or  to be made  by Nellcor, Sub  and P-B in  connection with the
Merger, including those representations set forth in the Merger Agreement and in
certificates of representations provided to us by Nellcor and P-B.

    Based upon and  subject to the  foregoing, the discussion  contained in  the
prospectus  included as  part of  the Registration  Statement (the "Prospectus")
under the  caption  "Certain Federal  Income  Tax Consequences,"  expresses  our
opinion  as to  the material  Federal income tax  consequences if  the Merger is
effected according to the terms of the Merger Agreement. Because this opinion is
being delivered prior to the Effective Time of the Merger, it must be considered
prospective and dependent upon future events.  In addition, you should be  aware
that  the discussion under the caption "Certain Federal Income Tax Consequences"
in the Prospectus represents our conclusions  as to the application of  existing
law  to the instant transactions and may not be applicable to certain classes of
P-B stockholders, including securities dealers, foreign persons and persons  who
acquired  their  P-B Common  Stock pursuant  to the  exercise of  employee stock
options or rights or otherwise as  compensation. There can be no assurance  that
changes in the law will not take place which could affect the Federal income tax
consequences  of the Merger or  that contrary positions may  not be taken by the
Internal Revenue Service.

Nellcor Incorporated
July 18, 1995
Page Two

    This opinion  is furnished  to you  solely for  use in  connection with  the
Registration  Statement. We hereby consent  to the filing of  this opinion as an
exhibit to the Registration Statement. We also consent to the references to  our
firm  name wherever appearing in the  Registration Statement with respect to the
discussion of the Federal income tax  consequences of the Merger, including  the
Prospectus constituting a part thereof, and any amendment thereto.

                                          Very truly yours,