Vespertilionid species are widely distributed in South America. They are highly diverse, with physiological and behavioral adaptations which allow them to extend their distributions into temperate areas. In Patagonia, this family is represented by seven species in three genera (Histiotus, Lasiurus and Myotis). In this study, we analyzed the distribution of two vespertilionid species, Lasiurus villosissimus and Myotis dinellii, including new southernmost records, and their relationship with environmental variables. Two different spatial scales were analyzed: a continental approach for species distribution analyses (South America), and local trapping of bats in northwestern Chubut province, Argentina. We present new southern limits for L. villosissimus and M. dinellii, and included new records for Patagonian bats. The big hoary bat L. villosissimus was recorded as the largest bat inhabiting Patagonia, relating it as a bat mainly inhabiting low, humid and temperate/warm areas. The little yellow bat M. dinellii, instead, is the smallest mammal and the smallest bat recorded in Patagonia to date, related mainly with dry, mid-altitude and temperate/warm areas.