Two new horse fly species, Dasybasis mancoi sp. nov. and D. huaynai sp. nov. (Diptera: Tabanidae: Diachlorini), are described from the Peruvian Andes near Cusco on the basis of morphological features, including those of the female genitalia. Digital photographs of both species and of the terminalia of both females and of one male are provided. The two new species are related to D. bulbula Coscarn & Philip, as evidenced by their similar morphological characteristics.