Antimicrobial activities against pathogenic E. coli and S. aureus of ethyl acetate extracts from fresh peels and dried peels of tropical citrus fruits including lime, kaffir lime and pomelo peels were compared. The extracts from dried peels had lost some antimicrobial activity (Table 1), although the drying process was performed at low temperature of 55oC. All extracts from both fresh and dried lime, kaffir lime and pomelo peels had antibacterial activity against S. aureus, but the ones from fresh peels showed higher inhibition (wider inhibitory zones). The extracts from fresh lime and kaffir lime peels inhibited growth of E. coli whereas no activity was observed with the ones from dried peels, indicating loss of certain inhibitory components during drying process, particularly volatile compounds.