The species richness and conservation status of primates in the Reserva Comunal Tamshiyacu-Tahuayo, northeastern Peru, located between the Yavari and Amazon rivers is reported. Two sites within a continuous forest were studied in the 322 500 ha reserve. Primate densities were estimated from censuses of 290 km of line transects using Fourier series expansion. Fourteen species of anthropoid primates have been confirmed to occur sympatrically in the Reserva Comunal Tamshiyacu-Tahuayo which is the greatest species richness of primates reported to date within a Peruvian conservation unit. Hunting by local inhabitants has decreased the densities and biomasses of Cebids in the reserve, but not Callitrichids. A management plan for hunting in the Reserva Comunal Tamshiyacu-Tahuayo has been developed to better conserve primates and other mammalian species. © 1993 Chapman & Hall.