Although 13 species of the genus Eumops have been documented in South America, none of them had been previously reported in Chile. Based on acoustic surveys, we report here the first record of this genus for the country. Fourteen echolocation sequences of the Western mastiff bat (Eumops perotis) were recorded in the valleys of Azapa, Lluta, and Camarones in the Arica and Parinacota region, northern Chile. Echolocation calls of E. perotis can be distinguished from other bat species in the region by its lower frequency range, longer call duration, and interpulse intervals. This finding adds a new genus and species for Chile and increases the known bat diversity in the country to 17 species.