August 1, 1996                                                      Exhibit 5.1




Nicollet Process Engineering, Inc.
420 North Fifth Street
Ford Centre, Suite 1040
Minneapolis, Minnesota 55401

Re:      Registration Statement on Form S-8
         1990 Stock Option Plan
         1995 Stock Incentive Plan

Ladies and Gentlemen:

We have acted as counsel to Nicollet Process Engineering, Inc., a Minnesota
corporation (the "Company"), in connection with the registration by the Company
of 1,000,000 shares of its Common Stock, no par value (the "Shares"), pursuant
to the Company's Registration Statement on Form S-8 for the Company's 1990 Stock
Option Plan and 1995 Amended and Restated Stock Incentive Plan (collectively,
the "Option Plans"), to be filed with the Securities and Exchange Commission on
August 1, 1996 (the "Registration Statement").

In acting as counsel for the Company and arriving at the opinions expressed
below, we have examined and relied upon originals or copies, certified or
otherwise identified to our satisfaction, of such records of the Company,
agreements and other instruments, certificates of officers and representatives
of the Company, certificates of public officials and other documents as we have
deemed necessary or appropriate as a basis for the opinions expressed herein.

In connection with our examination, we have assumed the genuineness of all
signatures, the authenticity of all documents tendered to us as originals, the
legal capacity of natural persons and the conformity to original documents of
all documents submitted to us as certified or photostatic copies.

Based on the foregoing, and subject to the qualifications and limitations set
forth herein, it is our opinion that:

1.       The Company has the corporate authority to issue the Shares in the
         manner and under the terms set forth in the Registration Statement.

2.       The Shares have been duly authorized and, when issued, delivered and
         paid for in accordance with the Option Plans referred to in the
         Registration Statement, will be validly issued, fully paid and
         nonassessable.

We express no opinion with respect to laws other than the laws of the State of
Minnesota and the federal laws of the United States of America, and we assume no
responsibility as to the applicability thereto, or the effect thereon, of the
laws of any other jurisdiction.

We hereby consent to the filing of this opinion as Exhibit 5.1 to the
Registration Statement and to its use as part of the Registration Statement.

We are furnishing this opinion to the Company solely for its benefit in
connection with the Registration Statement as described above. It is not to be
used, circulated, quoted or otherwise referred to for any other purpose.

Very truly yours,

OPPENHEIMER WOLFF & DONNELLY