Abstract: In 1957 uranium was discovered in the Vilcabamba district on the north flank of the Cordillera Vilcabamba, part of the Cordillera Oriental. This district contains principally small copper-nickel veins. Small lenses of uraninite occur in calcite veins cutting Permian Copacabana limestone. Uranium is most abundant marginal to centers of strongest copper-nickel mineralization. Leaching and oxidation are virtually absent because of Pleistocene glaciation. Four separate areas in which uranium has been identified are Huamanapi, Calderon, Minasmayo, and Negrillas. The Puntarayoc area, near Pampaconas, is considered a separate district. The deposits have been tested by trenching, drilling, and sampling concurrently with geologic reconnaissance mapping of the surrounding region.