Here we present the results of a herpetofauna survey carried out in the municipality of Porto Walter, southwest Amazon, Brazil, characterized by the presence of forested and deforested areas due to the development of agricultural activities. Nine trips were carried out between October 2014 to December 2015, totalizing 67 field days. Fifty-eight species of amphibians (57 anurans and one caudate) and 51 reptiles (25 lizards, 21 snakes, four chelonians, and one crocodilian) were found. The fossorial lizard Bachia scaea was reported for the first time in Acre State, extending its geographic distribution approximately 900 kilometers to the west. Most of the species recorded are typical in forests, which demonstrates the importance of forested areas in Porto Walter to maintain these populations and also emphasizes the need of studies on possible impacts of deforestation on amphibian and reptile populations.