To determine the species of Diptera and Coleoptera that visit and breed in carrion, four experiments, one for each season, were conducted from November 1992 to October 1993 in the vicinity of Campinas city, Southeastern Brazil. For each experiment two pigs weighting c. 10 kg were killed with a blow to the head with a blunt metallic object and immediately exposed, one in the shade and the other under sunlight. Adult insects and larvae leaving the carcass to pupate were collected daily. In addition, female blowflies were dissected in order to determine the stage of ovarian development. Five species of Calliphoridae: Chrysomya albiceps, C. megacephala, C.putoria, Phaenicia eximia and Hemilucilia segmentaria; three of Sarcophagidae; Pattonella intermutans, Liopygia ruficornis and Adiscochaeta ingens, and three of beetles: Dermestes maculatus, D. peruvianus (Dermestidae) and Necrobia rufipes (Cleridae), were considered of potential forensic importance, for they were able to breed in carrion exposed to natural environmental conditions. In addition, several fly species showed a definite seasonal pattern, with the Calliphoridae breeding more frequently during the warmer months of the year, and the Sarcophagidae preferring the cooler periods.