EXHIBIT 5

                     [BROBECK, PHLEGER & HARRISON LLP LOGO]


                               September 24, 1996



Biocryst Pharmaceuticals, Inc.
2190 Parkway Lake Drive
Birmingham, Alabama 35244

Ladies and Gentlemen:

          We have assisted in the preparation and filing by Biocryst
Pharmaceuticals, Inc. (the "Company") of a Registration Statement on Form S-3,
as amended through August 21, 1966 (the "Registration Statement"), with the
Securities and Exchange Commission, relating to the sale of up to 2,300,000
shares (the "Shares") of Common Stock, $0.01 par value (the "Common Stock"), of
the Company.  A form of underwriting agreement (the "Underwriting Agreement") is
filed as an exhibit to the Registration Statement.

          We have examined such records and documents and have made such
examination of laws as we considered necessary to form a basis for the opinion
set forth herein.  In our examination, we have assumed the genuineness of all
signatures, the authenticity of all documents submitted to us as originals, and
the conformity with the originals of all documents submitted to us as copies
thereof.

          Based upon and subject to the foregoing, we are of the opinion that
the Shares have been duly authorized and, when sold and paid for in accordance
with the terms of the Underwriting Agreement, well be validly issued, fully paid
and nonassessable.

          We hereby consent to the use of our name in the Registration Statement
under the caption "Legal Matters" in the related Prospectus and consent to the
filing of this opinion as an exhibit thereto.

                                             Very truly yours,



                                             /s/ BROBECK, PHLEGER & HARRISON LLP
                                             BROBECK, PHLEGER & HARRISON LLP