Valdiviomyia pucara new species is described from Neuquén Province, Argentina. A description of the new species is provided, as is a key for identifying the species of the genus. Type material of all known species, i.e. V. camrasi (Sedman), V. darwini (Shannon), V. edwardsi (Shannon and Aubertin), V. nigra (Shannon), V. ruficauda (Shannon), and holotype of Ocyptamus albimanus Bigot [=V. valdiviana (Philippi)], was studied. Morphological characters of the genus and the subgeneric groupings are discussed.