We report the first record of the genus Cavia and the species Cavia tschudii (Rodentia, Caviidae) in Catamarca province, northwestern Argentina, which represents a range extension of about 110 km southward for the species. The cranial and dental remains were recovered from an owl pellet sample found in eastern slopes of the Ambato range, at 1600 m elevation, in a highland grasslands-Chaco Serrano ecotone. According to the environmental continuity along the Ambato range, we suggest that the presence of C. tschudii in southernmost Catamarca and northern La Rioja province is likely.