Washington, D.C. 20549


Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940
OMB Number: 3235-0287
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hours per response: 0.5
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
1. Name and Address of Reporting Person*
Venkataraman Ganesh

(Last) (First) (Middle)


(City) (State) (Zip)
2. Issuer Name and Ticker or Trading Symbol
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
Director 10% Owner
X Officer (give title below) Other (specify below)
Senior V.P., Research
3. Date of Earliest Transaction (Month/Day/Year)
4. If Amendment, Date of Original Filed (Month/Day/Year)
6. Individual or Joint/Group Filing (Check Applicable Line)
X Form filed by One Reporting Person
Form filed by More than One Reporting Person
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4)
Code V Amount (A) or (D) Price
Common Stock 05/26/2005 S(1) 10,000 D $11 552,812 D
Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 6. Date Exercisable and Expiration Date (Month/Day/Year) 7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares
Explanation of Responses:
1. The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on February 24, 2005.
Exhibit 24.1 -- Power of Attorney
/s/ Ganesh Venkataraman 05/27/2005
** Signature of Reporting Person Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.
Exhibit 24.1


       Know all by these presents, that the undersigned 
hereby makes, constitutes and appoints each of Richard P. 
Shea and Michael Morneau, signing singly and each acting 
individually, as the undersigned's true and lawful 
attorney-in-fact with full power and authority as 
hereinafter described to:
       (1)	execute for and on behalf of the undersigned, in 
the undersigned's capacity as an officer of Momenta 
Pharmaceuticals, Inc. (the "Company"), Forms 3, 4, and 5 
(including any amendments thereto) in accordance with 
Section 16(a) of the Securities Exchange Act of 1934 and 
the rules thereunder (the "Exchange Act");
       (2)	do and perform any and all acts for and on behalf 
of the undersigned which may be necessary or desirable to 
prepare, complete and execute any such Form 3, 4, or 5, 
prepare, complete and execute any amendment or amendments 
thereto, and timely deliver and file such form with the 
United States Securities and Exchange Commission and any 
stock exchange or similar authority;
       (3)	seek or obtain, as the undersigned's 
representative and on the undersigned's behalf, information 
regarding transactions in the Company's securities from any 
third party, including
 brokers, employee benefit plan 
administrators and trustees, and the undersigned hereby 
authorizes any such person to release any such information 
to such attorney-in-fact and approves and ratifies any such 
release of information; and
       (4)	take any other action of any type whatsoever in 
connection with the foregoing which, in the opinion of such 
attorney-in-fact, may be of benefit to, in the best 
interest of, or legally required by, the undersigned, it 
being understood that the documents executed by such 
attorney-in-fact on behalf of the undersigned pursuant to 
this Power of Attorney shall be in such form and shall 
contain such terms and conditions as such attorney-in-fact 
may approve in such attorney-in-fact's discretion.
       The undersigned hereby grants to each such 
attorney-in-fact full power and authority to do and perform 
any and every act and thing whatsoever requisite, 
necessary, or proper to be done in the exercise of any of 
the rights and powers herein granted, as fully to all 
intents and purposes as the undersigned might or could do 
if personally present, with full power of substitution or 
revocation, hereby ratifying and confirming all that such 
attorney-in-fact, or such attorney-in-fact's substitute or 
substitutes, shall lawfully do or cause to be done by 
virtue of this power of attorney and the rights and powers 
herein granted.  The undersigned acknowledges that the 
foregoing attorneys-in-fact, in serving in such capacity at 
the request of the undersigned, are not assuming nor 
relieving, nor is the Company assuming nor relieving, any 
of the undersigned's responsibilities to comply with 
Section 16 of the Exchange Act.  The undersigned 
acknowledges that neither the Company nor the foregoing 
attorneys-in-fact assume (i) any liability for the 
undersigned's responsibility to comply with the requirement 
of the Exchange Act, (ii) any liability of the undersigned 
for any failure to comply with such requirements, or (iii) 
any obligation or liability of the undersigned for profit 
disgorgement under Section 16(b) of the Exchange Act.
       This Power of Attorney shall remain in full force and 
effect until the undersigned is no longer required to file 
Forms 3, 4, and 5 with respect to the undersigned's 
holdings of and transactions in securities issued by the 
Company, unless earlier revoked by the undersigned in a 
signed writing delivered to the foregoing 
       IN WITNESS WHEREOF, the undersigned has caused this 
Power of Attorney to be executed as of this 23rd day of May 

/s/ Ganesh Venkataraman		

 Ganesh Venkataraman		
Print Name