As filed with the Securities and Exchange Commission on December 31, 1996
                                                      Registration No. 333-
--------------------------------------------------------------------------------

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


                       SECURITIES AND EXCHANGE COMMISSION

                             WASHINGTON, D.C. 20549

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


                                    FORM S-8

                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933

                          ARONEX PHARMACEUTICALS, INC.
             (Exact name of registrant as specified in its charter)


               Delaware                                      76-0196535
    (State or other jurisdiction of                       (I.R.S. Employer
    incorporation or organization)                      Identification No.)

      3400 Research Forest Drive
         The Woodlands, Texas                                  77381
(Address of Principal Executive Offices)                     (Zip Code)

                        1997 EMPLOYEE STOCK PURCHASE PLAN
                            (Full title of the plan)

                              James M. Chubb, Ph.D.
                          Aronex Pharmaceuticals, Inc.
                           3400 Research Forest Drive
                           The Woodlands, Texas 77381
                     (Name and address of agent for service)

                                 (281) 367-1666
          (Telephone number, including area code, of agent for service)

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

                                    copy to:
                                 Jeffrey L. Wade
                             Andrews & Kurth L.L.P.
                        2170 Buckthorne Place, Suite 150
                           The Woodlands, Texas 77380
                                 (713) 220-4801

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


                         CALCULATION OF REGISTRATION FEE
<TABLE>
<CAPTION>


                                                          Proposed Maximum    Proposed Maximum
                                            Amount to      Offering Price        Aggregate             Amount of
Title of Securities to be Registered      be Registered     Per Share(1)      Offering Price(1)     Registration Fee
<S>                                      <C>              <C>              <C>                   <C>   
---------------------------------------- ---------------  ---------------- --------------------  --------------------
Common Stock, par value $0.001 per share  250,000 Shares        $9.75         $2,437,500               $739
======================================== ===============  ================ ====================  ====================
</TABLE>

(1)      Estimated  solely  for the  purpose  of  calculating  the amount of the
         registration  fee,  based  upon the  average of the high and low prices
         reported on The Nasdaq National Market of the Registrant's Common Stock
         on December 27, 1996, pursuant to Rule 457(c) and (h).
================================================================================



<PAGE>

                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3. INCORPORATION OF DOCUMENTS BY REFERENCE.

          Aronex  Pharmaceuticals,  Inc. (the "Company")  incorporates herein by
reference the following documents as of their respective dates as filed with the
Securities and Exchange Commission (the "Commission"):

          1. The  Company's  Annual  Report  on Form  10-K  for the  year  ended
     December 31, 1995, as amended.

          2. The Company's Quarterly Reports on Form 10-Q for the quarters ended
     March 31, 1996, June 30, 1996, and September 30, 1996.

          3. The  description  of the Common Stock  contained  in the  Company's
     Registration  Statement  on Form 8-A filed April 23,  1992,  including  any
     amendments and reports filed for the purpose of updating such description.

         All documents filed by the Company  pursuant to Sections 13(a),  13(c),
14 and 15(d) of the Exchange Act after the date of this  Registration  Statement
and prior to the filing of a  post-effective  amendment which indicates that all
securities  offered  hereby  have  been  sold  or  which  deregisters  all  such
securities then remaining unsold shall be deemed to be incorporated by reference
in this  Registration  Statement and to be a part hereof from the date of filing
such documents.

ITEM 4. DESCRIPTION OF SECURITIES.

         The  information   required  by  Item  4  is  not  applicable  to  this
registration statement since the class of securities to be offered is registered
under Section 12 of the Exchange Act.

ITEM 5. INTERESTS OF NAMED EXPERTS AND COUNSEL.

         The  information   required  by  Item  5  is  not  applicable  to  this
registration statement.

ITEM 6. INDEMNIFICATION OF DIRECTORS AND OFFICERS.

         Section 145 of the Delaware  General  Corporation  Law ("DGCL"),  inter
alia,  empowers a Delaware  corporation  to indemnify any person who was or is a
party  or is  threatened  to be  made a  party  to any  threatened,  pending  or
completed action, suit or proceeding (other than an action by or in the right of
the  corporation)  by reason of the fact that such  person is or was a director,
officer,  employee  or agent of the  corporation,  or is or was  serving  at the
request of the corporation as a director,  officer, employee or agent of another
corporation or other enterprise,  against expenses (including  attorneys' fees),
judgments, fines and amounts paid in settlement actually and reasonably incurred
by him in  connection  with such action,  suit or proceeding if he acted in good
faith and in a manner he reasonably believed to be in or not opposed to the best
interests  of the  corporation,  and,  with  respect to any  criminal  action or
proceeding, had no reasonable cause to believe his conduct was unlawful. Similar
indemnity is authorized for such persons against expenses (including  attorneys'
fees)  actually  and  reasonably  incurred  in  connection  with the  defense or
settlement of any such  threatened,  pending or completed action or suit if such
person  acted in good faith and in a manner he  reasonably  believed to be in or
not opposed to the best interests of the corporation,  and provided further that
(unless a court of competent  jurisdiction otherwise provides) such person shall
not have been adjudged liable to the corporation.  Any such  indemnification may
be made only as authorized in each  specific  case upon a  determination  by the
stockholders  or  disinterested  directors or by independent  legal counsel in a
written  opinion that  indemnification  is proper because the indemnitee has met
the applicable standard of conduct.

         Section 145 further  authorizes a corporation  to purchase and maintain
insurance on behalf of any person who is or was a director, officer, employee or
agent of the corporation, or is or was serving at the request of the corporation
as a director,  officer, employee or agent of another corporation or enterprise,
against  any  liability  asserted  against  him and  incurred by him in any such
capacity,  or arising out of his status as such,  whether or not the corporation
would  otherwise  have the power to indemnify him under Section 145. The Company
maintains  policies  insuring its and its  subsidiaries' 

                                      II-1

<PAGE>


officers and directors  against  certain  liabilities  for actions taken in such
capacities,  including  liabilities under the Securities Act of 1933, as amended
(the "Securities Act").

         Article VIII of the Amended and Restated  Certificate of  Incorporation
of the  Company  and  Article  VII of the  Bylaws  of the  Company  provide  for
indemnification  of the directors of the Company to the full extent permitted by
law, as now in effect or later  amended.  Article VII of the Bylaws also permits
the  indemnification to the same extent of officers,  employees or agents of the
Company  if,  and to the  extent,  authorized  by the  Board  of  Directors.  In
addition, the Bylaws provide for indemnification  against expenses incurred by a
director to be paid by the  Company at  reasonable  intervals  in advance of the
final  disposition  of  such  action,  suit or  proceeding  upon  receipt  of an
undertaking  by or on behalf of the  director or officer to repay such amount if
it shall be ultimately  determined  that he is not entitled to be indemnified by
the Company. The Bylaws further provide for a contractual cause of action on the
part of directors of the Company for  indemnification  claims that have not been
paid by the Company.

         The Company also has provided liability insurance for each director and
officer for certain  losses  arising  from claims or charges  made  against them
while acting in their capacities as directors or officers of the Company.

         Article  VII of the  Company's  Amended  and  Restated  Certificate  of
Incorporation,  as amended,  limits under certain circumstances the liability of
the Company's directors for a breach of their fiduciary duty as directors. These
provisions  do not eliminate the liability of a director (i) for a breach of the
director's duty of loyalty to the Company or its stockholders,  (ii) for acts or
omissions not in good faith or that involve intentional  misconduct or a knowing
violation  of  law,  (iii)  under  Section  174 of  the  DGCL  (relating  to the
declaration  of dividends  and purchase or  redemption of shares in violation of
the  DGCL) or (iv) for any  transaction  from  which  the  director  derived  an
improper personal benefit.

ITEM 7. EXEMPTION FROM REGISTRATION CLAIMED.

         Information  required by Item 7 is not applicable to this  Registration
Statement.


                                      II-2

<PAGE>



ITEM 8. EXHIBITS.

Exhibit
Number                             Description

4.1       Amended and Restated Certificate of Incorporation, as amended. Exhibit
          3.1 to the Company's  Quarterly  Report on Form 10-Q for the quarterly
          period ended June 30, 1996 is incorporated herein by reference.

4.2       Restated Bylaws.  Exhibit 3.2 to the Company's  Registration Statement
          on Form S-1 (No.  33-47418),  declared  effective by the Commission on
          July 10, 1992, is incorporated herein by reference.

4.3       Specimen  certificate for shares of Common Stock,  par value $.001 per
          share.  Exhibit 4.1 to the Company's Quarterly Report on Form 10-Q for
          the  quarterly  period ended June 30, 1996 is  incorporated  herein by
          reference.

5.1*      Opinion  of  Andrews  &  Kurth  L.L.P.,  as to  the  legality  of  the
          securities being registered.

23.1*     Consent of Arthur Andersen LLP

23.2*     Consent of Andrews & Kurth L.L.P.  (included  in the opinion  filed as
          Exhibit 5.1 to this Registration Statement).

24.1*     Power of Attorney (set forth on the signature  page  contained in Part
          II of this Registration Statement).

99.1*     Aronex Pharmaceuticals, Inc. 1997 Employee Stock Purchase Plan

---------------------------
*Filed with this Registration Statement.

ITEM 9. UNDERTAKINGS.

         The undersigned Registrant hereby undertakes:

         (a)      The undersigned Registrant hereby undertakes:

                  (1) To file,  during any  period in which  offers or sales are
         being made, a post-effective amendment to this registration statement:

                    (i) To include any prospectus  required by Section  10(a)(3)
               of the Securities Act of 1933; 

                    (ii) To  reflect  in the  prospectus  any  facts  or  events
               arising after the effective  date of the  registration  statement
               (or the most  recent  post-effective  amendment  thereof)  which,
               individually or in the aggregate,  represent a fundamental change
               in the  information  set  forth  in the  registration  statement.
               Notwithstanding the foregoing, any increase or decrease in volume
               of  securities  offered (if the total dollar value of  securities
               offered  would not  exceed  that  which was  registered)  and any
               deviation  from  the low or  high  end of the  estimated  maximum
               offering  range may be reflected in the form of prospectus  filed
               with the Commission pursuant to Rule 424(b) if, in the aggregate,
               the  changes  in  volume  and price  represent  no more than a 20
               percent change in the maximum aggregate  offering price set forth
               in the  "Calculation of Registration  Fee" table in the effective
               registration statement;


                    (iii) To include any  material  information  with respect to
               the  plan  of  distribution  not  previously   disclosed  in  the
               registration statement or any material change to such information
               in the registration statement;


                                       II-3

<PAGE>


                  Provided, however, that paragraphs (a)(1)(i) and (a)(1)(ii) do
         not apply if the  registration  statement  is on Form S-3,  Form S-8 or
         Form  F-3,   and  the   information   required  to  be  included  in  a
         post-effective  amendment by those  paragraphs is contained in periodic
         reports  filed with or furnished to the  Commission  by the  Registrant
         pursuant to Section 13 or Section  15(d) of the  Exchange  Act that are
         incorporated by reference in the registration statement.

                  (2) That, for the purpose of determining  any liability  under
         the Securities Act, each such post-effective  amendment shall be deemed
         to be a new registration  statement  relating to the securities offered
         therein,  and the  offering  of such  securities  at that time shall be
         deemed to be the initial bona fide offering thereof.

                  (3) To remove from  registration by means of a  post-effective
         amendment any of the securities being registered which remain unsold at
         the termination of the offering.

                  (b) The undersigned  registrant  hereby  undertakes  that, for
purposes of determining  any liability  under the  Securities Act of 1933,  each
filing of the  registrant's  annual report pursuant to Section 13(a) or 15(d) of
the Securities  Exchange Act of 1934 that is  incorporated  by reference in this
Registration  Statement  shall  be  deemed  to be a new  registration  statement
relating to the securities offered therein,  and the offering of such securities
at that time shall be deemed to be the initial bona fide offering thereof.

                  (c) Insofar as indemnification  for liabilities  arising under
the  Securities  Act of  1933  may  be  permitted  to  directors,  officers  and
controlling persons of the registrant pursuant to the foregoing  provisions,  or
otherwise, the registrant has been advised that in the opinion of the Securities
and  Exchange  Commission  such  indemnification  is  against  public  policy as
expressed in the Securities Act of 1933 and is, therefore, unenforceable. In the
event that a claim for indemnification  against such liabilities (other than the
payment by the registrant of expenses incurred or paid by a director, officer or
controlling  person of the registrant in the  successful  defense of any action,
suit or proceeding) is asserted by such director,  officer or controlling person
in connection with the securities being registered,  the registrant will, unless
in the  opinion  of its  counsel  the matter  has been  settled  by  controlling
precedent,  submit to a court of appropriate  jurisdiction  the question whether
such  indemnification  by it is  against  public  policy  as  expressed  in  the
Securities  Act of 1933 and will be governed by the final  adjudication  of such
issue.


                                      II-4

<PAGE>


                                   SIGNATURES

         Pursuant to the  requirements  of the Securities  Exchange Act of 1933,
the Registrant certifies that is has reasonable grounds to believe that it meets
all of the  requirements  for  filing  on  Form  S-8 and has  duly  caused  this
Registration Statement to be signed on its behalf by the undersigned,  thereunto
duly authorized,  in The Woodlands,  State of Texas on the 30th day of December,
1996.

                                         ARONEX PHARMACEUTICALS, INC.

                                         By:      /s/ James M. Chubb
                                            --------------------------------
                                                  James M. Chubb
                                                  President

         KNOW ALL MEN BY THESE PRESENTS,  that each of the undersigned  officers
and directors of Aronex Pharmaceuticals, Inc. (the "Company") hereby constitutes
and appoints James M. Chubb and Terance A. Murnane, or either of them (with full
power to each of them to act alone),  his true and lawful  attorney-in-fact  and
agent,  with full power of substitution and  resubstitution,  for him and on his
behalf and in his name,  place and stead,  in any and all  capacities,  to sign,
execute and file this  Registration  Statement under the Securities Act of 1933,
as  amended,  and  any  or  all  amendments   (including,   without  limitation,
post-effective amendments), with all exhibits and any and all documents required
to be filed with respect thereto, with the Securities and Exchange Commission or
any regulatory authority,  granting unto such  attorneys-in-fact and agents, and
each of them acting  alone,  full power and authority to do and perform each and
every act and thing requisite and necessary to be done in and about the premises
in order to  effectuate  the same,  as fully to all intents  and  purposes as he
himself might or could do if personally present, hereby ratifying and confirming
all that such  attorneys-in-fact and agents, or any of them, or their substitute
or substitutes, may lawfully do or cause to be done.

         PURSUANT  TO THE  REQUIREMENTS  OF THE  SECURITIES  ACT OF  1933,  THIS
REGISTRATION  STATEMENT  HAS  BEEN  SIGNED  BY  THE  FOLLOWING  PERSONS  IN  THE
CAPACITIES AND ON THE DATES INDICATED.

<TABLE>
<CAPTION>

Signature                                   Title                                        Date
---------                                   -----                                        ----
<S>                               <C>                                            <C>   

/s/ James M. Chubb                President and Director                         December 30, 1996
-----------------------------     (Principal Executive Officer)                         
James M. Chubb                  

/s/ Terance A. Murnane            Controller                                     December 30, 1996
-----------------------------     (Principal Financial and Accounting Officer)
Terance A. Murnane              

/s/ Martin P. Sutter              Chairman of the Board of Directors             December 30, 1996
-----------------------------
Martin P. Sutter                
                                  Director                                       December   , 1996
-----------------------------                                               
Gabriel Lopez-Berestein
                                  Director                                       December   , 1996 
----------------------------- 
Donald J. Brenner                                            

/s/ Geoffrey F. Cox               Director                                       December 30, 1996        
-----------------------------                                               
Geoffrey F. Cox

/s/ George B. Mackaness           Director                                       December 30, 1996     
-----------------------------    
George B. Mackaness
                                  Director                                       December   , 1996
-----------------------------                                                    
Gregory F. Zaic

</TABLE>

                                      II-5

<PAGE>



                                  EXHIBIT INDEX

Exhibit
Number                             Description

4.1       Amended and Restated Certificate of Incorporation, as amended. Exhibit
          3.1 to the Company's  Quarterly  Report on Form 10-Q for the quarterly
          period ended June 30, 1996 is incorporated herein by reference.

4.2       Restated Bylaws.  Exhibit 3.2 to the Company's  Registration Statement
          on Form S-1 (No.  33-47418),  declared  effective by the Commission on
          July 10, 1992, is incorporated herein by reference.

4.3       Specimen  certificate for shares of Common Stock,  par value $.001 per
          share.  Exhibit 4.1 to the Company's Quarterly Report on Form 10-Q for
          the  quarterly  period ended June 30, 1996 is  incorporated  herein by
          reference.

5.1*      Opinion  of  Andrews  &  Kurth  L.L.P.,  as to  the  legality  of  the
          securities
          being registered.

23.1*     Consent of Arthur Andersen LLP

23.2*     Consent of Andrews & Kurth L.L.P.  (included  in the opinion  filed as
          Exhibit 5.1 to this Registration Statement).

24.1*     Powerof Attorney (set forth on the signature  page  contained in Part
          II of this Registration Statement).

99.1* Aronex Pharmaceuticals, Inc. 1997 Employee Stock Purchase Plan

---------------------------
*Filed with this Registration Statement.
[{"type": "S-8", "sequence": "1", "description": "ARNONEX PHARMACEUTICALS, INC. FORM S-8", "secsgml_size_bytes": 22234}]
{"company-data": {"conformed-name": "ARONEX PHARMACEUTICALS INC", "cik": "0000854691", "assigned-sic": "2834", "irs-number": "760196535", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-19135", "film-number": "96689192"}, "business-address": {"street1": "3400 RESEARCH FOREST DR", "city": "THE WOODLANDS", "state": "TX", "zip": "77381", "phone": "7133671666"}, "mail-address": {"street1": "3400 RESEARCH FOREST DRIVE", "city": "THE WOODLANDS", "state": "TX", "zip": "77381"}}
As filed with the Securities and Exchange Commission on December 31, 1996
                                                      Registration No. 333-
--------------------------------------------------------------------------------

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

                       SECURITIES AND EXCHANGE COMMISSION

                             WASHINGTON, D.C. 20549

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

                                    FORM S-8

                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933

                          ARONEX PHARMACEUTICALS, INC.
             (Exact name of registrant as specified in its charter)

               Delaware                                      76-0196535
    (State or other jurisdiction of                       (I.R.S. Employer
    incorporation or organization)                      Identification No.)

      3400 Research Forest Drive
         The Woodlands, Texas                                  77381
(Address of Principal Executive Offices)                     (Zip Code)

                        1997 EMPLOYEE STOCK PURCHASE PLAN
                            (Full title of the plan)

                              James M. Chubb, Ph.D.
                          Aronex Pharmaceuticals, Inc.
                           3400 Research Forest Drive
                           The Woodlands, Texas 77381
                     (Name and address of agent for service)

                                 (281) 367-1666
          (Telephone number, including area code, of agent for service)

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

                                    copy to:
                                 Jeffrey L. Wade
                             Andrews & Kurth L.L.P.
                        2170 Buckthorne Place, Suite 150
                           The Woodlands, Texas 77380
                                 (713) 220-4801

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

                         CALCULATION OF REGISTRATION FEE
Proposed Maximum    Proposed Maximum
                                            Amount to      Offering Price        Aggregate             Amount of
Title of Securities to be Registered      be Registered     Per Share(1)      Offering Price(1)     Registration Fee
---------------------------------------- ---------------  ---------------- --------------------  --------------------
Common Stock, par value $0.001 per share  250,000 Shares        $9.75         $2,437,500               $739
======================================== ===============  ================ ====================  ====================
(1)      Estimated  solely  for the  purpose  of  calculating  the amount of the
         registration  fee,  based  upon the  average of the high and low prices
         reported on The Nasdaq National Market of the Registrant's Common Stock
         on December 27, 1996, pursuant to Rule 457(c) and (h).
================================================================================
PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3. INCORPORATION OF DOCUMENTS BY REFERENCE.

          Aronex  Pharmaceuticals,  Inc. (the "Company")  incorporates herein by
reference the following documents as of their respective dates as filed with the
Securities and Exchange Commission (the "Commission"):

          1. The  Company's  Annual  Report  on Form  10-K  for the  year  ended
     December 31, 1995, as amended.

          2. The Company's Quarterly Reports on Form 10-Q for the quarters ended
     March 31, 1996, June 30, 1996, and September 30, 1996.

          3. The  description  of the Common Stock  contained  in the  Company's
     Registration  Statement  on Form 8-A filed April 23,  1992,  including  any
     amendments and reports filed for the purpose of updating such description.

         All documents filed by the Company  pursuant to Sections 13(a),  13(c),
14 and 15(d) of the Exchange Act after the date of this  Registration  Statement
and prior to the filing of a  post-effective  amendment which indicates that all
securities  offered  hereby  have  been  sold  or  which  deregisters  all  such
securities then remaining unsold shall be deemed to be incorporated by reference
in this  Registration  Statement and to be a part hereof from the date of filing
such documents.

ITEM 4. DESCRIPTION OF SECURITIES.

         The  information   required  by  Item  4  is  not  applicable  to  this
registration statement since the class of securities to be offered is registered
under Section 12 of the Exchange Act.

ITEM 5. INTERESTS OF NAMED EXPERTS AND COUNSEL.

         The  information   required  by  Item  5  is  not  applicable  to  this
registration statement.

ITEM 6. INDEMNIFICATION OF DIRECTORS AND OFFICERS.

         Section 145 of the Delaware  General  Corporation  Law ("DGCL"),  inter
alia,  empowers a Delaware  corporation  to indemnify any person who was or is a
party  or is  threatened  to be  made a  party  to any  threatened,  pending  or
completed action, suit or proceeding (other than an action by or in the right of
the  corporation)  by reason of the fact that such  person is or was a director,
officer,  employee  or agent of the  corporation,  or is or was  serving  at the
request of the corporation as a director,  officer, employee or agent of another
corporation or other enterprise,  against expenses (including  attorneys' fees),
judgments, fines and amounts paid in settlement actually and reasonably incurred
by him in  connection  with such action,  suit or proceeding if he acted in good
faith and in a manner he reasonably believed to be in or not opposed to the best
interests  of the  corporation,  and,  with  respect to any  criminal  action or
proceeding, had no reasonable cause to believe his conduct was unlawful. Similar
indemnity is authorized for such persons against expenses (including  attorneys'
fees)  actually  and  reasonably  incurred  in  connection  with the  defense or
settlement of any such  threatened,  pending or completed action or suit if such
person  acted in good faith and in a manner he  reasonably  believed to be in or
not opposed to the best interests of the corporation,  and provided further that
(unless a court of competent  jurisdiction otherwise provides) such person shall
not have been adjudged liable to the corporation.  Any such  indemnification may
be made only as authorized in each  specific  case upon a  determination  by the
stockholders  or  disinterested  directors or by independent  legal counsel in a
written  opinion that  indemnification  is proper because the indemnitee has met
the applicable standard of conduct.

         Section 145 further  authorizes a corporation  to purchase and maintain
insurance on behalf of any person who is or was a director, officer, employee or
agent of the corporation, or is or was serving at the request of the corporation
as a director,  officer, employee or agent of another corporation or enterprise,
against  any  liability  asserted  against  him and  incurred by him in any such
capacity,  or arising out of his status as such,  whether or not the corporation
would  otherwise  have the power to indemnify him under Section 145. The Company
maintains  policies  insuring its and its  subsidiaries' 

                                      II-1
officers and directors  against  certain  liabilities  for actions taken in such
capacities,  including  liabilities under the Securities Act of 1933, as amended
(the "Securities Act").

         Article VIII of the Amended and Restated  Certificate of  Incorporation
of the  Company  and  Article  VII of the  Bylaws  of the  Company  provide  for
indemnification  of the directors of the Company to the full extent permitted by
law, as now in effect or later  amended.  Article VII of the Bylaws also permits
the  indemnification to the same extent of officers,  employees or agents of the
Company  if,  and to the  extent,  authorized  by the  Board  of  Directors.  In
addition, the Bylaws provide for indemnification  against expenses incurred by a
director to be paid by the  Company at  reasonable  intervals  in advance of the
final  disposition  of  such  action,  suit or  proceeding  upon  receipt  of an
undertaking  by or on behalf of the  director or officer to repay such amount if
it shall be ultimately  determined  that he is not entitled to be indemnified by
the Company. The Bylaws further provide for a contractual cause of action on the
part of directors of the Company for  indemnification  claims that have not been
paid by the Company.

         The Company also has provided liability insurance for each director and
officer for certain  losses  arising  from claims or charges  made  against them
while acting in their capacities as directors or officers of the Company.

         Article  VII of the  Company's  Amended  and  Restated  Certificate  of
Incorporation,  as amended,  limits under certain circumstances the liability of
the Company's directors for a breach of their fiduciary duty as directors. These
provisions  do not eliminate the liability of a director (i) for a breach of the
director's duty of loyalty to the Company or its stockholders,  (ii) for acts or
omissions not in good faith or that involve intentional  misconduct or a knowing
violation  of  law,  (iii)  under  Section  174 of  the  DGCL  (relating  to the
declaration  of dividends  and purchase or  redemption of shares in violation of
the  DGCL) or (iv) for any  transaction  from  which  the  director  derived  an
improper personal benefit.

ITEM 7. EXEMPTION FROM REGISTRATION CLAIMED.

         Information  required by Item 7 is not applicable to this  Registration
Statement.

                                      II-2
ITEM 8. EXHIBITS.

Exhibit
Number                             Description

4.1       Amended and Restated Certificate of Incorporation, as amended. Exhibit
          3.1 to the Company's  Quarterly  Report on Form 10-Q for the quarterly
          period ended June 30, 1996 is incorporated herein by reference.

4.2       Restated Bylaws.  Exhibit 3.2 to the Company's  Registration Statement
          on Form S-1 (No.  33-47418),  declared  effective by the Commission on
          July 10, 1992, is incorporated herein by reference.

4.3       Specimen  certificate for shares of Common Stock,  par value $.001 per
          share.  Exhibit 4.1 to the Company's Quarterly Report on Form 10-Q for
          the  quarterly  period ended June 30, 1996 is  incorporated  herein by
          reference.

5.1*      Opinion  of  Andrews  &  Kurth  L.L.P.,  as to  the  legality  of  the
          securities being registered.

23.1*     Consent of Arthur Andersen LLP

23.2*     Consent of Andrews & Kurth L.L.P.  (included  in the opinion  filed as
          Exhibit 5.1 to this Registration Statement).

24.1*     Power of Attorney (set forth on the signature  page  contained in Part
          II of this Registration Statement).

99.1*     Aronex Pharmaceuticals, Inc. 1997 Employee Stock Purchase Plan

---------------------------
*Filed with this Registration Statement.

ITEM 9. UNDERTAKINGS.

         The undersigned Registrant hereby undertakes:

         (a)      The undersigned Registrant hereby undertakes:

                  (1) To file,  during any  period in which  offers or sales are
         being made, a post-effective amendment to this registration statement:

                    (i) To include any prospectus  required by Section  10(a)(3)
               of the Securities Act of 1933; 

                    (ii) To  reflect  in the  prospectus  any  facts  or  events
               arising after the effective  date of the  registration  statement
               (or the most  recent  post-effective  amendment  thereof)  which,
               individually or in the aggregate,  represent a fundamental change
               in the  information  set  forth  in the  registration  statement.
               Notwithstanding the foregoing, any increase or decrease in volume
               of  securities  offered (if the total dollar value of  securities
               offered  would not  exceed  that  which was  registered)  and any
               deviation  from  the low or  high  end of the  estimated  maximum
               offering  range may be reflected in the form of prospectus  filed
               with the Commission pursuant to Rule 424(b) if, in the aggregate,
               the  changes  in  volume  and price  represent  no more than a 20
               percent change in the maximum aggregate  offering price set forth
               in the  "Calculation of Registration  Fee" table in the effective
               registration statement;

                    (iii) To include any  material  information  with respect to
               the  plan  of  distribution  not  previously   disclosed  in  the
               registration statement or any material change to such information
               in the registration statement;

                                       II-3
Provided, however, that paragraphs (a)(1)(i) and (a)(1)(ii) do
         not apply if the  registration  statement  is on Form S-3,  Form S-8 or
         Form  F-3,   and  the   information   required  to  be  included  in  a
         post-effective  amendment by those  paragraphs is contained in periodic
         reports  filed with or furnished to the  Commission  by the  Registrant
         pursuant to Section 13 or Section  15(d) of the  Exchange  Act that are
         incorporated by reference in the registration statement.

                  (2) That, for the purpose of determining  any liability  under
         the Securities Act, each such post-effective  amendment shall be deemed
         to be a new registration  statement  relating to the securities offered
         therein,  and the  offering  of such  securities  at that time shall be
         deemed to be the initial bona fide offering thereof.

                  (3) To remove from  registration by means of a  post-effective
         amendment any of the securities being registered which remain unsold at
         the termination of the offering.

                  (b) The undersigned  registrant  hereby  undertakes  that, for
purposes of determining  any liability  under the  Securities Act of 1933,  each
filing of the  registrant's  annual report pursuant to Section 13(a) or 15(d) of
the Securities  Exchange Act of 1934 that is  incorporated  by reference in this
Registration  Statement  shall  be  deemed  to be a new  registration  statement
relating to the securities offered therein,  and the offering of such securities
at that time shall be deemed to be the initial bona fide offering thereof.

                  (c) Insofar as indemnification  for liabilities  arising under
the  Securities  Act of  1933  may  be  permitted  to  directors,  officers  and
controlling persons of the registrant pursuant to the foregoing  provisions,  or
otherwise, the registrant has been advised that in the opinion of the Securities
and  Exchange  Commission  such  indemnification  is  against  public  policy as
expressed in the Securities Act of 1933 and is, therefore, unenforceable. In the
event that a claim for indemnification  against such liabilities (other than the
payment by the registrant of expenses incurred or paid by a director, officer or
controlling  person of the registrant in the  successful  defense of any action,
suit or proceeding) is asserted by such director,  officer or controlling person
in connection with the securities being registered,  the registrant will, unless
in the  opinion  of its  counsel  the matter  has been  settled  by  controlling
precedent,  submit to a court of appropriate  jurisdiction  the question whether
such  indemnification  by it is  against  public  policy  as  expressed  in  the
Securities  Act of 1933 and will be governed by the final  adjudication  of such
issue.

                                      II-4
SIGNATURES

         Pursuant to the  requirements  of the Securities  Exchange Act of 1933,
the Registrant certifies that is has reasonable grounds to believe that it meets
all of the  requirements  for  filing  on  Form  S-8 and has  duly  caused  this
Registration Statement to be signed on its behalf by the undersigned,  thereunto
duly authorized,  in The Woodlands,  State of Texas on the 30th day of December,
1996.

                                         ARONEX PHARMACEUTICALS, INC.

                                         By:      /s/ James M. Chubb
                                            --------------------------------
                                                  James M. Chubb
                                                  President

         KNOW ALL MEN BY THESE PRESENTS,  that each of the undersigned  officers
and directors of Aronex Pharmaceuticals, Inc. (the "Company") hereby constitutes
and appoints James M. Chubb and Terance A. Murnane, or either of them (with full
power to each of them to act alone),  his true and lawful  attorney-in-fact  and
agent,  with full power of substitution and  resubstitution,  for him and on his
behalf and in his name,  place and stead,  in any and all  capacities,  to sign,
execute and file this  Registration  Statement under the Securities Act of 1933,
as  amended,  and  any  or  all  amendments   (including,   without  limitation,
post-effective amendments), with all exhibits and any and all documents required
to be filed with respect thereto, with the Securities and Exchange Commission or
any regulatory authority,  granting unto such  attorneys-in-fact and agents, and
each of them acting  alone,  full power and authority to do and perform each and
every act and thing requisite and necessary to be done in and about the premises
in order to  effectuate  the same,  as fully to all intents  and  purposes as he
himself might or could do if personally present, hereby ratifying and confirming
all that such  attorneys-in-fact and agents, or any of them, or their substitute
or substitutes, may lawfully do or cause to be done.

         PURSUANT  TO THE  REQUIREMENTS  OF THE  SECURITIES  ACT OF  1933,  THIS
REGISTRATION  STATEMENT  HAS  BEEN  SIGNED  BY  THE  FOLLOWING  PERSONS  IN  THE
CAPACITIES AND ON THE DATES INDICATED.
Signature                                   Title                                        Date
---------                                   -----                                        ----
/s/ James M. Chubb                President and Director                         December 30, 1996
-----------------------------     (Principal Executive Officer)                         
James M. Chubb                  

/s/ Terance A. Murnane            Controller                                     December 30, 1996
-----------------------------     (Principal Financial and Accounting Officer)
Terance A. Murnane              

/s/ Martin P. Sutter              Chairman of the Board of Directors             December 30, 1996
-----------------------------
Martin P. Sutter                
                                  Director                                       December   , 1996
-----------------------------                                               
Gabriel Lopez-Berestein
                                  Director                                       December   , 1996 
----------------------------- 
Donald J. Brenner                                            

/s/ Geoffrey F. Cox               Director                                       December 30, 1996        
-----------------------------                                               
Geoffrey F. Cox

/s/ George B. Mackaness           Director                                       December 30, 1996     
-----------------------------    
George B. Mackaness
                                  Director                                       December   , 1996
-----------------------------                                                    
Gregory F. Zaic
II-5
EXHIBIT INDEX

Exhibit
Number                             Description

4.1       Amended and Restated Certificate of Incorporation, as amended. Exhibit
          3.1 to the Company's  Quarterly  Report on Form 10-Q for the quarterly
          period ended June 30, 1996 is incorporated herein by reference.

4.2       Restated Bylaws.  Exhibit 3.2 to the Company's  Registration Statement
          on Form S-1 (No.  33-47418),  declared  effective by the Commission on
          July 10, 1992, is incorporated herein by reference.

4.3       Specimen  certificate for shares of Common Stock,  par value $.001 per
          share.  Exhibit 4.1 to the Company's Quarterly Report on Form 10-Q for
          the  quarterly  period ended June 30, 1996 is  incorporated  herein by
          reference.

5.1*      Opinion  of  Andrews  &  Kurth  L.L.P.,  as to  the  legality  of  the
          securities
          being registered.

23.1*     Consent of Arthur Andersen LLP

23.2*     Consent of Andrews & Kurth L.L.P.  (included  in the opinion  filed as
          Exhibit 5.1 to this Registration Statement).

24.1*     Powerof Attorney (set forth on the signature  page  contained in Part
          II of this Registration Statement).

99.1* Aronex Pharmaceuticals, Inc. 1997 Employee Stock Purchase Plan

---------------------------
*Filed with this Registration Statement.