Thirty-four adults of Physalaemus albonotatus (20 males and 14 females) were collected near the city of Corrientes, Province of Corrientes, Argentina (27°28'S - 58°50'W) between January 2001 and September 2004. Adults of four nematode species, Strongyloides sp., Oswaldocruzia sp., Cosmocerca podicipinus, Cosmocerca parva and larvae of two other species, Spiroxys sp. and Physaloptera sp. were recovered from the digestive tract, lungs and gastric mucosa. We present morphologic characters (some with scanning electron microscopy), morphometric information and range extensions for these nematode species. This is the first report of nematode parasites of P. albonotatus from Argentina.