Exhibit 5.1

                     Dickstein Shapiro Morin & Oshinsky LLP
                     1177 Avenue of the Americas, 41st Floor
                             New York, NY 10036-2714
                               Tel: (212) 835-1400
                               Fax: (212) 997-9880

                                                    November 1, 2001

Board of Directors
Discovery Laboratories, Inc.
350 South Main Street, Suite 307
Doylestown, PA 18901

                         Discovery Laboratories, Inc.--
                       Registration Statement on Form S-3

Gentlemen:

            We have acted as counsel for Discovery Laboratories, Inc., a
Delaware corporation (the "Company"), in connection with the preparation of the
registration statement on Form S-3, and any amendments thereto (the
"Registration Statement"), as filed with the Securities and Exchange Commission
(the "Commission") under the Securities Act of 1933 (the "Act"), on October 31,
2001, for the registration under the Act of up to 4,440,222 shares (the
"Shares") of the Company's common stock, par value $0.001 per share (the "Common
Stock"), comprised of 3,562,759 shares of Common Stock which are issued and are
outstanding (the "Shares"), 712,552 shares (the "Class F Warrant Shares") of
Common Stock which are issuable upon the exercise of certain Class F warrants of
the Company (the "Class F Warrants") and 164,911 shares (the "Placement Warrant
Shares") of Common Stock which are issuable upon the exercise of certain
Placement Warrants of the Company (the "Placement Warrants"). The Shares are to
be offered for resale on a delayed or continuous basis pursuant to Rule 415
promulgated under the Securities Act by certain selling stockholders of the
Company named in the Registration Statement (the "Selling Stockholders").

            In rendering this opinion, we have relied upon, among other things,
our examination of certain records of the Company, including without limitation,
the Company's Certificate of Incorporation, as amended, the Company's Bylaws and
resolutions of the Board of Directors. We have also examined certificates of the
Company's officers and of public officials, and have reviewed such questions of
law and made such other inquiries, as we have deemed necessary or appropriate
for the purpose of rendering this opinion. As to various questions of fact
material to this opinion, we have also relied upon representations and
warranties of the Company and upon such certificates and other


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instruments of officers of the Company and public officials furnished to us by
the Company, in each case without independent investigation or verification.

            In addition, without any independent investigation or verification,
we have assumed (i) the genuineness of all signatures, (ii) the authenticity of
all documents submitted to us as originals and the conformity with the original
documents of all documents submitted to us as certified, conformed or
photostatic copies, (iii) the authority of all persons signing any document
other than the officers of the Company, where applicable, signing in their
capacity as such, (iv) the enforceability of all the documents we have reviewed
in accordance with their respective terms against the parties thereto and (v)
the truth and accuracy of all matters of fact set forth in all certificates and
other instruments furnished to us.

            Based on and subject to the assumptions, qualifications and
limitations set forth herein, we are of the opinion that:

            1. The Shares that are presently issued and outstanding have been
duly and validly authorized and issued and are fully paid and nonassessable.

            2. The Class F Warrant Shares have been duly authorized for issuance
pursuant to the Class F Warrants, and when issued and delivered in the manner
described in the Class F Warrants against full payment of the consideration set
forth therein, will be validly issued, fully paid and nonassessable.

            3. The Placement Warrant Shares have been duly authorized for
issuance pursuant to the Placement Warrants, and when issued and delivered in
the manner described in the Placement Warrants against full payment of the
consideration set forth therein, will be validly issued, fully paid and
nonassessable.

            We do not express any opinion as to the laws of other states or
jurisdictions other than the laws of the State of New York, the General
Corporation Law of the State of Delaware and the federal law of the United
States. No opinion is expressed as to the effect that the law of any other
jurisdiction may have upon the subject matter of the opinion expressed herein
under conflicts of law principles, rules and regulations or otherwise.

            This opinion is limited to the specific issues addressed herein, and
no opinion may be inferred or implied beyond that expressly stated herein. We
assume no obligation to revise or supplement this opinion should the present
laws of the State of New York or the General Corporation Law of the State of
Delaware be changed by legislative action, judicial decision or otherwise.

            We hereby consent to the filing of this opinion with the Commission
as Exhibit 5.1 to the Registration Statement and the reference to us under the
heading "Legal Matters" in the prospectus included in Part I of the Registration
Statement. In giving this


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consent, we do not admit that we are within the category of persons whose
consent is required by Section 7 of the Securities Act or the rules and
regulations promulgated thereunder by the Commission.

            This opinion is furnished to you in connection with the filing of
the Registration Statement and is not to be used, circulated, quoted or
otherwise relied upon for any other purposes.

            We wish to call your attention to the fact that the fair market
value of all securities of the Company that are beneficially owned by attorneys
of this Firm exceeds $50,000.

                                      Very truly yours,


                                      /s/ Dickstein Shapiro Morin & Oshinsky LLP