The Chinchiná River basin is located on the western slope of the Colombian Central Andes. This basin provides ecosystem services such as water provision for >500,000 people, but has suffered considerable ecosystem degradation, and the information on its biodiversity is limited. We inventoried the non-volant mammals in the Caldas’ Central Hydroelectric (CHEC) Reserve in the Chinchiná River basin, in the Caldas department. We detected 18 species of mammals, present the first record of Puma yagouaroundi for the high Chinchiná River basin, the first record of Leopardus wiedii for the basin and a new altitudinal record of this felid for the Colombian Central Andes, and we also report a melanistic individual of Leopardus tigrinus. We also provide the first record of Conepatus semistriatus for Caldas department. We highlight the importance of preserving forests on the Chinchiná River basin such as the CHEC Reserve, since they made serve to connect Andean forest with paramo areas on the National Natural Park Los Nevados, adding possible habitat for movements of Puma concolor and other mammals.