The present report is related to an oxyurid nematode recovered from a reptilian host, Mabuya frenata (Cope, 1862) and the proposal of Skrjabinodon helicostai sp.n., based mainly on findings referring to the lateral alae, position of excretory pore and vulvar apertures, cuticular spines of the tail and aspect of the eggs. The examination of types of Skrjabinodon capacyupanquii (Freitas, Vicente & Ibanez, 1968) from a Peruvian lizard, indicated the reallocation of this species in the genus Thelandros Wedl., 1862, as T. capacyupanquii comb.n., based on the diameter of the caudal appendage of males and position of the vulvar aperture. The new species described herein represents the first report of a species of the genus Skrjabinodon Inglis, 1968 in South America.