The present study reports a natural infection of emus, Dromaius novaehollandiae, by the nematode Procyrnea uncinipenis. Five adult emus from a scientific breeding farm at North Fluminense State University located in the city of Campos dos Goytacazes, Rio de Janeiro state, Brazil were necropsied, and their gastrointestinal tract were collected and examined for the presence of parasites from October 2013 to November 2015. Two of the five (40%) emus necropsied were infected with nematodes, and a portion of the nematodes were processed for light microscopy. In addition, two other nematodes (a male and a female) were prepared for scanning electron microscopy. In a female bird, one nematode was collected in the proventriculus and two nematodes in the gizzard and in the male bird four nematodes were collected in the gizzard. The morphological and morphometric analyzes allowed to identify the nematodes as P. uncinipenis, this being the first report of an infection by P. uncinipenis in emus. Therefore, we infer that these emus were naturally infected by nematodes that were considered specific to rheas.