Ten species of brachycephalid frogs from Costa Rica, Craugastor crassidigitus, Craugastor fitzingeri, Craugastor gollmeri, Craugastor melanostictus, Craugastor ranoides, Craugastor taurus, Craugastor underwoodi, Eleutherodactylus caryophyllaceus, Eleutherodactylus cruentus, Eleutherodactylus ridens, were examined for helminths. Found were 2 species of Digenea, Gorgoderina megacetabularis, Mesocoelium monas; 1 species of Cestoda, Cylindrotaenia americana; 13 species of Nematoda: adults of Aplectana incerta, Aplectana itzocanensis, Cosmocerca parva, Cosmocerca podicipinus, Cosmocercoides variabilis, Falcaustra costaricae, Hedruris heyeri, Ochoterenella digiticauda, Oswaldocruzia costaricensis, Oxyascaris mcdiarmidi, Rhabdias savagei, larva of Physaloptera sp. and Porrocaecum sp., and 2 species of Acanthocephala, Anuracanthorhynchus lutzi and the second species represented by centrorhynchid cystacanths. Mean number of helminth species per infected frog species was 5.0 ± 0.9 SE (range 2–10). The supracommunity of Costa Rican brachycephalid frogs is discussed. Forty-seven new host records are reported. A helminth list for each species studied is established.