The total index of fleas, lice and acari were determined on mammals captured in Maracá Island, Roraima State, Brazil, from November 1987 to February 1989, In view of the limiting or critical values attributed to flea index, proposed as a complementary measure for plague surveillance, some wild rodent would have been exposed to this infec-tion. The total indexwas11.5 and the prevalent flea was Polygenis klagesi klagesi, observed in the dry season. The highest numbers of ectopanasites per host were: 244 for Proechimys guyannensis, 193 for Proechimys sp. and 108 for Botomys sp. Species with the highest indices of infestation were P. klagesi klagesi on Proechimys sp.; Gliricola sp. ri., Tur apicalis and Tur. aymara on P. guyannensis. The single infestations were the most prevalent, while the double and others were equivalent. With the exception of proe chimys sp., all species of hosts presented single infestation . Only Laelaps dearmsi and Gliricola porcelli occurred in single infestations.