Summary: We examined the endoparasites of wild nutria from the native region of South America. Individuals were infected with nineteen species, including Nematoda (82. 0 %), Protozoa (46. 1 %), Trematoda (33. 3 %) and Cestoda (12. 8%). Coccidia (Eimeria sp. or Isospora sp.), Strongyloides myopotami and Trichuris myocastoris were the most abundant and prevalent parasites. The diversity of parasite collected on individual hosts ranged from one to four species. There was no significant association between either the age or the sex of the nutria and the prevalence of parasitism, except that the number of infested nutria less than 1 year by Nematoda was significantly higher than in older individuals. Additionally, Cryptosporidium spp. and Giardia spp. were demonstrated in fecal samples, although scarcely. In general, the accessions were found in good bodily condition and carrying low parasite burdens. These numbers appeared insufficient to indicate gastrointestinal parasitism or parasitic disease.Facultad de Ciencias Veterinarias