One thousand fifty-two anurans representing 11 families (41 species)-Bufonidae: Crepidophryne epiotica (n = 2), Incilius coccifer (n = 21), Incilius conifera (n = 2), Incilius luetkenii (n = 48), Incilius valliceps (n = 5), Rhaebo haematiticus (n = 6), Rhine marina (n = 77); Craugastoridae: Craugastor bransfordii (n = 1), Craugastor cuaquero (n = 1), Craugastor fitzingeri (n = 54), Craugastor megacephalus (n = 6), Craugastor noblei (n = 4), Craugastor podiciferus (n = 3), Craugastor ranoides (n = 4), Craugastor stejnegerianus (n = 3), Craugastor underwoodi (n = 2); Dendrobatidae: Oophaga pumilio (n = 5); Eleutherodactylidae: Diasporus diastema (n = 4); Hylidae: Agalychnis callidryas (n = 14), Duellmanohyla rufioculis (n = 3), Dendropsophus ebraccatus (n = 10), Dendropsophus microcephalus (n = 8), Isthmohyla lancasteri (n = 7), Scinax boulengeri (n = 22), Scinax elaeochrous (n = 13), Smilisca baudinii = 83) Smilisca phaeota (n = 8), Smilisca puma (n = 4), Trachycephahts venulosus (n = 41); Leptodactylidae: Leptodactylus fragilis (n = 16), Leptodactylus melanonotus (n = 17), Leptodactylus pentadactylus (n = 22), Leptodactylus poecilochilus (n = 26); Leiuperidae: Engystomops pustulosus (n = 27); Microhylidae: Hypopachus variolosus (n = 32); Ranidae: Lithobates forreri (n = 114), Lithobates taylori (n = 24), Lithobates (n = 267), Lithobates warszewitschii (n = 32); Rhinophrynidae: Rhinophrya dorsalis (n = 4); Strabomantidae: Pristimantis ridens (n = 10)-collected in the Area de Conservacion Guanacaste, Costa Rica, were necropsied. Gravid nematodes representing 20 species-Africana telfordi, Aplectana hylambatis, Aplectana incerta, Aplectana itzocanensis, Cosmocerca pan,a, Cosmocerca podicipinus, Cosmocercella minor, Cosmocercoides variabilis Cruzia empera, Falcaustra costaricae, Foleyellides striatus, Ochoterenella digiticauda, Oswaldocruzia costaricensis, Parapharyagodon duniae, Rhabdias Rhabdias pseudosphaerocephala, Rhabdias savagei, Schrankiana inconspicata, Spiroxys figueiredoi, Subulascaris falcaustriformis-and larvae representing 5 species-Ascaridae gen. sp., Contracaecum sp, Eustrongylides sp., Physaloptera sp., Physocephalus sp.-were found. One hundred thirteen new host records are reported.