The results regarding the first inventory of species richness and conservation grade for lizards and snakes from Reserva Forestal La Tronosa (RFT) are presented as a contribution to the national herpetological knowledge, Based on collects and observations, it is confirmed that 32 reptile species, grouped in 25 genres distributed in 10 families. From species richness, 17 are lizards of which three are considered “Vulnerable” and one “In Danger”; and 15 are snakes, and only one corresponds to “Vulnerable”. We emphasized that the perturbations and habitat fragmentation, as well as species isolation, are the most influential causes of individuals absences, which under less adverse conditions for sure would have been found.