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                                                                       EXHIBIT 5

                  [Wildman, Harrold, Allen & Dixon Letterhead]

Nanophase Technologies Corporation
1319 Marquette Drive
Romeoville, Illinois  60446

         Re:      Registration Statement on Form S-8

Ladies and Gentlemen:

         We have acted as counsel to Nanophase Technologies Corporation, a
Delaware corporation (the "Company"), in connection with the filing with the
Securities and Exchange Commission of a registration statement on Form S-8 (the
"Registration Statement") under the Securities Act of 1933, as amended (the
"Act") relating to 900,000 shares (the "Shares") of the Company's common stock,
par value $.01 per share, which may be issued and sold pursuant to the Company's
Equity Compensation Plan (the "Plan").

         In connection with this opinion, we have examined and are familiar with
originals or copies, certified or otherwise identified to our satisfaction, of
(i) the Plan; (ii) the Registration Statement; (iii) the Certificate of
Incorporation, as amended, of the Company; (iv) the By-laws of the Company; and
(v) such other documents as we have deemed necessary and appropriate as a basis
for the opinion set forth below. In rendering our opinion set forth below, we
have assumed the authenticity of all documents submitted to us as originals, the
genuineness of all signatures and the conformity to authentic originals of all
documents submitted to us as copies. We have also assumed the legal capacity for
all purposes relevant hereto of all natural persons and, with respect to all
parties to agreements or instruments relevant hereto other than the Company,
that such parties had the requisite power and authority (corporate or otherwise)
to execute, deliver and perform such agreements or instruments, that such
agreements or instruments have been duly authorized by all requisite action
(corporate or otherwise), executed and delivered by such parties and that such
agreements or instruments are the valid, binding and enforceable obligations of
such parties. As to questions of fact material to our opinions, we have relied
upon certificates of officers of the Company and of public officials.

         Based upon and subject to the foregoing, we are of the opinion that the
Shares have been duly authorized and, assuming full payment is made for the
Shares, when issued pursuant to the terms of the Plan, the Shares will be
validly issued, fully paid and non-assessable.

         Our opinions expressed above are limited to the Delaware General
Corporation Law.

         We hereby consent to the filing of this opinion as Exhibit 5 to the
Registration Statement.

Dated:  November 29, 2001                   Very truly yours,

                                             /s/ Wildman, Harrold, Allen & Dixon



