Three unpublished fossil primate specimens from Patagonia (Argentina) are reported here. They are part of the Tournouër collection housed at the Muséum national d'Histoire naturelle in Paris, France, and correspond to a partial mandible collected in 1902, and one upper deciduous premolar and one upper permanent molar collected in 1899. The partial mandible comes from the early Miocene sediments in the Coyle river area (Santa Cruz Province, Argentina), and is attributable to Homunculus patagonicusAmeghino, 1891. It adds to the several specimens assigned to Homunculus patagonicus that were collected since the times of the Ameghino brothers in the area, between the rivers Coyle and Gallegos. Two other dental specimens came from Colhue-Huapi (Chubut province, Argentina). Both are here assigned to Mazzonicebus almendraeKay, 2010, the only known fossil primate in the early Miocene levels of Gran Barranca, in the Colhue-Huapi area. This contribution provides new morphological information concerning the mandible and dentition of HomunculusAmeghino, 1891, and the first evidence of the deciduous dentition of MazzonicebusKay, 2010.