Abstract The occurrence of ectoparasites in wild nutria is poorly understood. Fifty-five livetrapped wild nutria (Myocastor coypus) from its indigenous region were examined for ectoparasites after capture from December 2013 to December 2014. The captures came from the Buenos Aires Province, by far the area of the country most densely populated by nutria, characterized as a temperate grassland, which are prime areas for sustained agriculture. Only one species of chewing lice (Pitrufquenia coypus, Marelli, 1932), one flea (Nosopsyllus fasciatus, Bosc, 1800) and one tick (Rhipicephalus sanguineus, Latreille, 1806) were collected. Fourteen percent of the animals were infested and P.coypus, an obligate parasite of the nutria, which was the most prevalent ectoparasite. N. fasciatus and R. sanguineus occurrence remains controversial as they may or may not be some accidental host species. To our knowledge, this is the first comprehensive and systematic survey of ectoparasites in wild nutria from the southern hemisphere, the indigenous region of this species.