POWER OF ATTORNEY
Know all by these presents, that the undersigned hereby constitutes and appoints 
each of  John F. Haley, Trevor K. Ross and J. Andres Cedron, acting singly, the 
undersigned's true and lawful attorney-in-fact to:
1.        execute for and on behalf of the undersigned, in the undersigned's capacity as a 
director and/or officer of MercadoLibre, Inc. (the "Company"), Forms 3, 4, and 5 
in accordance with Section 16(a) of the Securities Exchange Act of 1934 and the 
rules thereunder;
2.        do and perform any and all acts for and on behalf of the undersigned which may 
be necessary or desirable to complete and execute any such Form 3, 4, or 5 and 
timely file such form with the United States Securities and Exchange 
Commission and any stock exchange or similar authority; and
3.        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 
interests 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 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, have lawfully done or caused to be done in 
the past, or shall lawfully do or cause to be done in the future, 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 is the Company assuming, any of the undersigned's 
responsibilities to comply with Section 16 of the Securities Exchange Act of 1934.
        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 attorneys-in-fact.
        IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to be 
executed as of this 7th day of August, 2007.
                                                                                                
                                        /s/ Emiliano Calemzuk                                          
                                        Signature