Results are here presented on mosquito catches performed in a coastal lowland farm - Granjas Calábria, in Jacarepaguá, city of Rio de Janeiro, Brazil, from August 1981 to July 1983. Our objectives were to determine the local species and to study their frequency in different environments and methods of capture. We obtained 20.472 adult mosquitoes, belonging to 50 species, several of which are known vectors of human diseases in other areas. Nine species are reported for the first time in the State of Rio de Janeiro. Ma. titillans was the more commom species in the catches of adultspecimens, followed by Ae. scapularis, Ph. deanei. Ph. davisi, Cx. saltanensis, Ae. taeniorhynchus and Ph. theobaldi. ma. titillans was also the most numerous on human bait. The mosquito fauna obtained in light-trap was quite distinct from that of captures on human and animal baits, the most numerous mosquito being Ur. lowi. The catches in the open country were less productive than in the residual forest except for some species, like ma. titillans, Cq. venezuelensis, Cx. amazonensis and Wy. leucostigma which were equally or more frequent in the opposite situation.