Ancognatha aymara Mondaca, new species, from the Andes mountains in Parinacota province in northern Chile, is described and illustrated. This species has been misidentified during the past 65 years, but an exhaustive review of the Chilean specimens formerly identified as Ancognatha lutea Erichson revealed it is an undescribed species. Photographs of adults, male genitalia, and other external features of taxonomic value are presented. Notes on distribution, habitat, and natural history are also provided.