The Andean-Amazon foothills represent a biodiversity hotspot in southern Colombia (Kattan et al. 2004, Bass et al. 2010) but deforestation in the region is occurring at an alarming rate (Hernández et al. 1992) and security problems have made access difficult. Biological surveys are needed in this region to document the local fauna and to help generate strategies to preserve it. In this study, we report the first preliminary inventory of large and medium-sized terrestrial mammals for the Alto Fragua Indi-Wasi National Park.