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REEDSMITH


                                                                    Exhibits 5.1
                                                                        and 23.2



September 5, 2001


DUSA Pharmaceuticals, Inc.
25 Upton Drive
Wilmington, Massachusetts 02061


Re:     DUSA Pharmaceuticals, Inc. (the "Company")
        Post-Effective Amendment No. 1 to Registration Statements on Form S-8


Gentlemen:

We have examined the Company's Post-Effective Amendment No. 1 on Form S-8 (the
"Registration Statement") to the Company's Form S-8 registration statements
(file numbers 333- 92259 and 333-57890), which is being filed with the
Securities and Exchange Commission (the "SEC") in connection with the
registration under the Securities Act of 1933, as amended (the "Act") of Six
Hundred Fifty-Six Thousand Fifty-Four (656,054) shares (the "Shares") of the
Company's common stock, without par value (the "Common Stock") which may be
issued pursuant to the DUSA Pharmaceuticals, Inc. 1996 Omnibus Plan, as amended
(the "Plan"). The Plan has been further amended to increase the number of shares
available for issuance under the Plan from fifteen percent (15%) of the number
of shares of Common Stock outstanding to twenty percent (20%) of the number of
shares of Common Stock outstanding or a maximum of Two Million Seven Hundred
Fifty-Three Thousand Three Hundred Twenty-Eight (2,753,328) shares of Common
Stock.

This opinion is being furnished in accordance with the requirements of Item 8 of
Form S-8 and Item 601(b)(5)(i) of Regulation S-K.

As legal counsel to the Company, we have examined the proceedings taken and
proposed to be taken in connection with the issuance, sale and payment of
consideration for the Shares under the Plan. We have also examined the original
or a photostatic or certified copy of (i) the Certificate of Incorporation of
the Company, and all amendments to the Certificate of Incorporation filed by the
Company in the Office of the Secretary of State of the State of New Jersey; (ii)
the By-laws of the Company; and (iii) such records of corporate proceedings and
other documents as we have deemed necessary in order to enable us to express the
opinion set forth below. 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



                                                                                        
                                                                Princeton Forrestal Village         Delaware
                                                                136 Main Street - Suite 250       New Jersey
                                                                   Princeton, NJ 08540-7839         New York
                                                                               609.987.0050     Pennsylvania
Steven J. Picco                                                            Fax 609.951.0824         Virginia
Office Administrative Partner                                                                 Washington, DC



                                                                    
Formed in the Commonwealth of Pennsylvania                             r  e  e  d  s  m  i  t  h  .  c  o  m

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DUSA Pharmaceuticals, Inc.
September 5, 2001
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original of all documents submitted to us as copies thereof. Our opinion set
forth below is limited to the Business Corporation Law of the State of New
Jersey.

Based on the foregoing examination, subject to the assumptions stated and
relying on statements of fact contained in the documents that we have examined,
we are of the opinion that the Shares have been duly authorized and that when
issued and sold in the manner described in the Plan and pursuant to the
agreement which may accompany each grant under the Plan, the Shares will be
legally and validly issued, fully paid and non-assessable.

We hereby consent to the filing of this opinion as an exhibit to the
Registration Statement. We also consent to the reference to our firm's name
wherever appearing in the Registration Statement, including any prospectus
constituting a part thereof, and any amendments thereto. This opinion may be
incorporated by reference in any abbreviated registration statement filed
pursuant to General Instruction E of Form S-8 under the Act with respect to the
Registration Statement.


Very truly yours,

s/Reed Smith LLP

REED SMITH LLP