Between 2000 and 2010, digestive tracts collected from carnivore carcasses found in southern Brazil were analyzed to determine the frequency and proportion of items constituting the diets of each species. Material was collected and analyzed from 194 animals of 10 species: Cerdocyon thous, Lycalopex gymnocercus (Canidae), Procyon cancrivorus (Procyonidae), Galictis cuja (Mustelidae), Conepatus chinga (Mephitidae), Leopardus colocolo, Leopardus geoffroyi, Leopardus guttulus, Leopardus wiedii, and Puma yagouaroundi (Felidae). Most of these species are sympatric, which makes them potential competitors when sharing, to a greater or lesser degree, the same resources. The food niche breadth was relatively narrow, demonstrating that even generalist species, such as the crab-eating raccoon, used food resources rather unequally. An extensive overlap (>90%) in food niches was found among the cat species, the grison, and the Pampas fox, which had diets based on rodents. Crab-eating raccoons occupied a different food niche, based on aquatic or semiaquatic prey and fruits. Conepatus chinga was unique in exploiting arthropods and insect larvae as basic dietary items.