[LETTER HEAD OF DECHERT LLP]

                                                                     Exhibit 5.1

May 2, 2005

Bluefly, Inc.
42 West 39th Street
New York, New York 10018

Ladies and Gentlemen:

        On the date hereof, Bluefly, Inc., a Delaware corporation (the
"Company"), intends to transmit for filing with the Securities and Exchange
Commission (the "Commission"), a Registration Statement under the Securities Act
of 1933, as amended (the "Act"), on Form S-8 (the "Registration Statement"),
relating to 12,886,473 shares (the "Shares") of common stock, par value $0.01
per share, of the Company, which are being offered pursuant to the Company's
2005 Stock Incentive Plan (the "Plan"). This opinion is an exhibit to the
Registration Statement.

        We have at times acted as special counsel to the Company in connection
with certain corporate and securities matters, and in such capacity we are
familiar with the various corporate and other proceedings relating to the
proposed offer and sale of the Shares as contemplated by the Registration
Statement.

        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 Company's Certificate of Incorporation as presently in effect, (ii) the
Company's By-Laws as presently in effect, (iii) minutes and other instruments
evidencing actions taken by the Company's directors and stockholders, (iv) the
Plan and (v) the form of option agreements, which we understand will be used by
the Company in connection with grants under the Plan. In our examination of all
such agreements, documents, certificates and instruments, we have assumed the
genuineness of all signatures, the authenticity of all agreements, documents,
certificates and instruments submitted to us as originals and the conformity
with the originals of all agreements, documents, certificates and instruments
submitted to us as certified, conformed or photostatic copies. Insofar as this
opinion relates to securities to be issued in the future, we have assumed that
all applicable laws, rules and regulations in effect at the time of such
issuance will be the same as such laws, rules and regulations in effect as of
the date hereof. With your permission, we have relied on the certification of
the general counsel of the Company as to certain matters of fact.

<PAGE>

May 2, 2005
Page2

        Our opinion herein is based solely upon the General Corporation Law of
the State of Delaware, and we express no opinion with respect to any other laws
(including, without limitation, the application of the securities or "Blue Sky"
laws of any state to the offer and/or sale of the Shares).

        Insofar as our opinion set forth below covers Shares (the "Covered
Shares") that are currently subject to options (the "Existing Options") issued
under the Company's 1997 Stock Option Plan or 2000 Stock Option Plan, our
opinion assumes that such Existing Options shall have lapsed or otherwise been
terminated without having been exercised and that the Covered Shares subject to
such Existing Options shall have been returned to the status of authorized and
unissued prior to issuance under the Plan.

        Based on the foregoing, and subject to and in reliance upon the accuracy
and completeness of the information relevant thereto provided to us, it is our
opinion that the Shares have been duly authorized, and (subject to the
effectiveness of the Registration Statement and compliance with applicable state
laws (including securities laws) of the states in which the Shares may be
offered and sold), when issued in accordance with the terms of the Plan and any
applicable option agreement issued thereunder, 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 and as an exhibit to any filing made by the Company under
the securities or other laws of any state of the United States in which the
Shares may be offered and sold. In giving such consent, we do not thereby admit
that we are in the category of persons whose consent is required under Section 7
of the Act, or the rules and regulations of the Commission thereunder.

        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 purpose, except as expressly provided in the preceding
paragraph, without our express written consent. This opinion is rendered to you
as of the date hereof, and we undertake no obligation to advise you of any
change in any applicable law or in facts or circumstances which might affect any
matters or opinions set forth herein.

                                                     Very truly yours,


                                                     DECHERT LLP

Dechert:  RAG, DSR, JRA
