EXHIBIT 5.1

September 29, 2004


The Board of Directors
Tektronix, Inc.
14200 SW Karl Braun Drive
Beaverton, OR  97077

We have acted as counsel for Tektronix, Inc., an Oregon corporation (the
"Company"), in connection with the Registration Statement on Form S-3,
Registration No. 333-117455 (the "Registration Statement") filed by the Company
with the Securities and Exchange Commission under the Securities Act of 1933, as
amended (the "Act"), relating to the resale by selling shareholders of up to
2,973,235 shares of Common Stock, without par value (including the associated
preferred stock purchase rights), of the Company (the "Shares") pursuant to the
terms of the Agreement and Plan of Merger dated as of June 29, 2004 (the "Merger
Agreement"), among the Company, Inet Technologies, Inc., a Delaware corporation,
Impala Merger Corp., a Delaware corporation ("Merger Corp.") and a wholly owned
subsidiary of the Company, and Impala Acquisition Co. LLC, a Delaware limited
liability company ("LLC") and a wholly owned subsidiary of the Company, pursuant
to which Merger Corp. will merge with and into Inet (the "Merger"), immediately
followed by the merger of Inet with and into the LLC (the "LLC Merger" and
together with the Merger, sometimes referred to as the "Combination").

We have reviewed the corporate action of the Company in connection with this
matter and have examined the documents, corporate records, and other instruments
we deemed necessary for the purposes of this opinion.

In rendering this opinion, we have assumed the genuineness of all signatures,
the authenticity of all documents submitted to us as originals, the conformity
to authentic original documents of all documents submitted to us as copies, and
that before the issuance of any of the Shares:

      (a) The Merger Agreement shall have been adopted and approved by the
requisite vote of the stockholders of Inet;

      (b) All other conditions to the completion of the Combination set forth in
the Merger Agreement shall have been satisfied or waived; and

The Board of Directors
September 29, 2004
Page 2


      (c) The Shares shall have been issued and delivered in the manner
contemplated by the Merger Agreement.

Based upon the foregoing, it is our opinion that the Shares, when issued,
delivered and sold in the manner described in the Registration Statement, will
be validly issued, fully paid and nonassessable.

We are qualified to practice law in the state of Oregon and we do not express
any opinions in this letter concerning any law other than the laws of the state
of Oregon and the federal laws of the United States of America.

This opinion is furnished solely for the benefit of the Company and may not be
filed with or furnished to any individual, entity, association, agency or other
person and may not be quoted or referred to, orally or in writing, in whole or
in part, without our prior written consent. We hereby consent to the filing of
this opinion as an exhibit to the Registration Statement and to the reference to
our firm in the prospectus constituting a part thereof. In giving such consent,
we do not thereby admit that we are in the category of persons whose consents
are required under Section 7 of the Act.

Very truly yours,


/s/ Stoel Rives LLP

STOEL RIVES LLP