EXHIBIT 99.1

[ENZO LOGO OMITTED]                                             NEWS RELEASE
                                                             ENZO BIOCHEM, INC.
                                                             527 MADISON AVENUE
                                                             NEW YORK, NY 10022

FOR IMMEDIATE RELEASE
CONTACT: STEVE ANREDER
         (212) 532-3232

                     ENZO BIOCHEM REPORTS OPERATING RESULTS
                          FOR FISCAL 2004 FIRST QUARTER

                               ------------------

FARMINGDALE, NY, December 15, 2003 - Enzo Biochem, Inc. (NYSE:ENZ), a leading
biotechnology company specializing in gene identification and genetic and immune
regulation technologies for diagnostic and therapeutic applications, today
reported operating results for the first fiscal quarter ended October 31, 2003.

         For the three month period, total revenues amounted to $10.3 million,
compared with $17.4 million in the corresponding year-earlier period. Gross
profit margin was 73.7%, compared with 80.5% a year ago. The net loss for the
first fiscal quarter amounted to $0.3 million, or ($0.01) per share, fully
diluted, compared to net income of $3.7 million, or $0.12 per share, fully
diluted, in the corresponding year-ago period. The results reflect primarily the
absence of shipments of research products by Enzo Life Sciences to a single
customer that accounted for an unusually strong order flow in the year-ago first
fiscal quarter.

         Cash flow for the quarter remained positive. Working capital as of
October 31, 2003, amounted to $97.6 million, and cash, cash equivalents and
marketable securities totaled $78.6 million.

         First fiscal quarter research and development expenses increased
slightly, to $1.9 million, reflecting clinical trial activities and other
research projects. Selling, general and administrative expenses declined
slightly to $3.4 million, from $3.5 million in the corresponding year-ago
period, while legal expenses increased $0.2 million, to $1.0 million.

         Revenues at Enzo Clinical Labs in the fiscal first quarter increased
8.2%, to $7.5 million, compared with $6.9 million in the corresponding
year-earlier period. Gross profit margin of 69% was comparable to the year-ago
first quarter, while pre-tax income amounted to $0.7 million. Enzo Clinical Labs
is benefiting from continued focus on its core office-based physician clientele.
The Clinical Labs has added personnel to its marketing staff, and is targeting
additional service centers and expansion into nearby markets not now served.

         Enzo Life Sciences has moved forward with an aggressive marketing
program designed to more directly service its end users, while simultaneously
positioning the Company for upcoming product line expansion. The program
involves continued increases of the direct field sales force, a comprehensive
advertising campaign, increased attendance at top industry trade meetings, and
publications in leading scientific journals. This effort is directed towards
accelerating the revenue growth in subsequent quarters, while at the same time,
bringing the Company into more direct contact with its customer base.




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Enzo Biochem, Inc. - Page 2

         Enzo Therapeutics last month received the final clearance to proceed
with a Phase I/II clinical trial of its Stealth Vector(R) HGTV43(TM) gene
construct for HIV infection. This study, to be conducted at the New York
Presbyterian Hospital-Weill-Medical College of Cornell University, in New York
City, is expected to begin early in calendar year 2004. Enrollment in the Phase
II randomized double blind clinical trial of Enzo's study drug for the
management of Crohn's Disease has been completed. Preparations for a Phase II
double-blind clinical trial for EHT899, the Company's medicine for hepatitis B
virus-associated chronic hepatitis, are proceeding. In addition, an application
has been filed to initiate a new clinical trial for the treatment of hepatitis C
virus infection utilizing the Company's novel small molecule immune modulation
platform.

         "Enzo Biochem continues to make significant progress," said Barry
Weiner, President. "Our program for expanding Life Sciences' direct sales
efforts is a very positive step for the Company as we move towards a more
centralized marketing approach for our proprietary products. Enzo Clinical Labs
is strongly positioned to continue its growth, and the Company's therapeutic
pipeline is growing and offers important new potential treatments for a variety
of medical conditions. Enzo Biochem, Inc. enjoys a strong financial position and
continues to be cash positive. We remain excited and confident regarding the
outlook."

ABOUT ENZO

         Enzo Biochem is engaged in the research, development and manufacture of
innovative health care products based on molecular biology and genetic
engineering techniques, and in providing diagnostic services to the medical
community. The Company's proprietary labeling and detection products for gene
sequencing and genetic analysis, with approximately 200 patents worldwide, are
sold to the life sciences market throughout the world. The Company's therapeutic
division is in various stages of clinical evaluation of its proprietary gene
medicine for HIV-1 infection and its proprietary immune regulation medicines for
hepatitis B and hepatitis C infection and for Crohn's Disease. The Company also
holds a patent covering a method and materials for correcting point mutations or
small insertions or deletions of genetic material that would allow for editing
and correcting certain abnormalities in genes. For more information visit our
website www.enzo.com.
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         EXCEPT FOR HISTORICAL INFORMATION, THE MATTERS DISCUSSED IN THIS NEWS
RELEASE MAY BE CONSIDERED "FORWARD-LOOKING" STATEMENTS WITHIN THE MEANING OF
SECTION 27A OF THE SECURITIES ACT OF 1933, AS AMENDED AND SECTION 21E OF THE
SECURITIES EXCHANGE ACT OF 1934, AS AMENDED. SUCH STATEMENTS INCLUDE
DECLARATIONS REGARDING THE INTENT, BELIEF OR CURRENT EXPECTATIONS OF THE COMPANY
AND ITS MANAGEMENT. INVESTORS ARE CAUTIONED THAT ANY SUCH FORWARD-LOOKING
STATEMENTS ARE NOT GUARANTEES OF FUTURE PERFORMANCE AND INVOLVE A NUMBER OF
RISKS AND UNCERTAINTIES THAT COULD MATERIALLY AFFECT ACTUAL RESULTS. THE COMPANY
DISCLAIMS ANY OBLIGATIONS TO UPDATE ANY FORWARD-LOOKING STATEMENT AS A RESULT OF
DEVELOPMENTS OCCURRING AFTER THE DATE OF THIS PRESS RELEASE.


         A CONFERENCE CALL CONDUCTED BY ENZO BIOCHEM, INC. MANAGEMENT WILL TAKE
PLACE ON TUESDAY, DECEMBER 16, 2003 AT 8:30 A.M. (ET). IT CAN BE ACCESSED BY
DIALING 888-338-6461, INTERNATIONAL CALLERS CAN DIAL 973-935-8509. YOU MAY ALSO
LISTEN OVER THE INTERNET AT WWW.VCALL.COM. TO LISTEN TO THE LIVE CALL ON THE
INTERNET, PLEASE GO TO THE WEB SITE AT LEAST FIFTEEN MINUTES EARLY TO REGISTER,
DOWNLOAD AND INSTALL ANY NECESSARY AUDIO SOFTWARE. FOR THOSE WHO CANNOT LISTEN
TO THE LIVE BROADCAST, A REPLAY WILL BE AVAILABLE THROUGH MIDNIGHT DECEMBER 28,
2003, SHORTLY FOLLOWING THE LIVE CALL. FOR REPLAY, DIAL 877-519-4471
(973-341-3080 INTERNATIONALLY). YOU WILL BE PROMPTED FOR PIN NUMBER 4368231.



                                - Table follows -



Enzo Biochem, Inc. - Page 3



                               ENZO BIOCHEM, INC.
                      SELECTED STATEMENT OF OPERATIONS DATA



                                                           Three Months Ended
                                                                October 31,
                                                           2003          2002
                                                          ------        ------
                                                       (In thousands, except per
                                                               Share data)
                                                               (unaudited)

Operating revenues                                       $10,273        $17,356

Income (loss) before (provision) benefit
            for income taxes                               ($816)        $6,047
(Provision) benefit for income taxes                        $493        ($2,359)
                                                         -------        -------

Net income (loss)                                          ($323)        $3,688
                                                         =======        =======

Basic earnings (loss) per share                           ($0.01)         $0.12
                                                         -------        -------
Diluted earnings (loss) per share                         ($0.01)         $0.12
                                                         -------        -------

Common share - basic                                      30,006         29,885
Common share - diluted                                    30,006         30,492







                           SELECTED BALANCE SHEET DATA

                                                 October 31, 2003  July 31, 2003
                                                      (unaudited)      (audited)
                                                             (in thousands)

Cash and Marketable Securities                           $78,625        $78,422
Working Capital                                          $97,596        $97,724
Stockholders' Equity                                    $109,294       $109,381
Total Assets                                            $115,545       $115,878