Two species of leptodactylid frogs, the marbled white-lipped frog, Leptodactylus elenae, and the pointed belly frog, Leptodactylus podicipinus, collected in Corrientes Province, Argentina, were examined for nematode parasites. Four adult species of nematodes belonging to 2 families (Cosmocercidae and Rhabdiasidae) were found parasitizing lungs and intestines: Aplectana delirae and Cosmocerca podicipinus in L. elenae; and Cosmocerca parva, Cosmocerca podicipinus, and Rhabdias sp. in L. podicipinus. This is the first report of nematode parasites for L. elenae and the second for L. podicipinus in Argentina. Aplectana delirae and Rhabdias sp. represent new host records.