Rural inhabitants in Amazonia can overexploit many mammalian species by game hunting, and tropical forests lose their value as a source of game meat when mammal populations decline. Implementing a sustainable hunt should reduce overexploitation of animals, and therefore help retain the value of intact Amazonian ecosystems. Rural folk in the Tahuayo region of the Reserva Comunal Tamshiyacu-Tahuayo of northeastern Peru appear to be overharvesting primates and lowland tapir Tapirus terrestris, but are apparently not overexploiting artiodactyls and large rodents. Converting the current overhunting in Tahuayo to a more sustainable harvest would require cessation of hunting of overexploited species and the setting of artiodactyl and large rodent harvests at or below current levels. Costs of implementing a more sustainable hunt in Tahuayo would incur a 26% reduction of economic benefits for hunters and reduce the extraction of mammalian biomass by 35%. © 1993.