Hedruris heyeri n. sp. (Nematoda: Hedruridae) from the stomach of Lithobates warszewitschii from Costa Rica is described and illustrated. Hedruris heyeri n. sp. represents the 22^nd species assigned to the genus and is distinguished from other species by the distribution pattern of caudal papillae of the male: 9 pairs posterior papillae (2 pairs precloacal, 1 pair adcloacal and 6 pairs postcloacal). Acanthocephalus lutzi (Hamann, 1891) is reassigned as Anuracanthorhynchus lutzi (Hamann, 1891) n. comb. Other helminths found include three species of Digenea (Gorgoderina diaster, Gorgoderina megacetabularis, and Mesocoelium monas), one species of Cestoda (represented by proteocephalid plerocercoids), and nine species of Nematoda (Aplectana incerta, Aplectana itzocanensis, Cosmocerca podicipinus, Falcaustra costaricae, Oswaldocruzia costaricensis, Porrocaecum sp., Raillietnema lynchi, and Rhabdias savagei).