<PAGE>
EXHIBIT 5
BELL, BOYD & LLOYD LLC
Three First National Plaza
70 West Madison Street, Suite 3300
Chicago, Illinois 60602-4207
312-372-1121 Fax: 312-372-2098
July 13, 2000
PathoGenesis Corporation
201 Elliott Avenue West
Seattle, Washington, 98119
PathoGenesis Corporation 1999 Employee Stock Option Plan and
PathoGenesis Corporation Employee Stock Purchase Plan
Registration Statement on Form S-8
-----------------------------------------------------
Ladies and Gentlemen:
We have acted as counsel to PathoGenesis Corporation, a Delaware
corporation (the "Company"), in connection with the preparation, execution and
filing of the registration statement on Form S-8 of the Company (the
"Registration Statement"), which covers 1,050,000 shares of common stock, par
value $.001 per share, of the Company (the "Shares"), to be offered from time to
time under the Company's 1999 Employee Stock Option Plan, as amended, and the
Company's Employee Stock Purchase Plan, as amended (collectively, the "Plans").
We have examined originals, or copies certified or otherwise identified to our
satisfaction, of the Plans and such other documents, corporate and other
records, certificates and other papers as we deemed it necessary to examine for
the purposes of this opinion.
Based upon the foregoing, we are of the opinion that:
1. The Company is a corporation duly organized and legally existing
under the law of the State of Delaware.
2. The Company has taken all action necessary to authorize (i) the
Plans, (ii) the offer for sale of the Shares pursuant to the
Plans, and (iii) the issuance of the shares of its common stock,
$.001 par value, in accordance with the Plans.
3. The Shares when issued in accordance with the Plans will, upon
such issuance, constitute legally issued, fully paid and
nonassessable shares of common stock, $.001 par value, of the
Company.
We hereby consent to the filing of this Opinion Letter as an exhibit
to the Registration Statement for the registration of the Shares under the
Securities Act of 1933. In giving this consent, we do not admit that we are
within the category of persons whose consent is required by Section 7 of the
Securities Act of 1933.
Very truly yours,
BELL, BOYD & LLOYD LLC