In the Brazilian Pantanal, we observed collared peccaries (Pecari tajacu) associating with South American coatis (Nasua nasua) 13 times and three times with black howler monkeys (Alouatta caraya). The scansorial coati drop fruit whilst feeding that both collared peccaries and other coatis consume. Young coatis were also observed chewing on the pulp left over from seeds spat out by collared peccaries who had removed the hard exocarp. Both species react to each other’s alarm calls. Peccaries also benefited from the fruits dropped by black howler monkeys. Ecologically, coatis are omnivores; but taxonomically, they are carnivores. To our knowledge, the collared peccary/coati association is the first report of an interspecific association between an ungulate and a carnivore.