The present paper comprises a systematic survey of nematodes found in 88 specimens of 24 species of freshwater fishes in Venezuela in 1992 and 1994. The following 13 species of nematodes were recorded: Adults: Guyanema longispiculum Moravec, Prouza et Royero, 1996, Guyunema sp., Procamallanus (Spiracamallanus) inupinatus Travassos, Artigas et Pereira, 1928, P. (S.) krameri (Petter, 1974) comb, n., P. (S.) pintoi (Kohn et Fernandes, 1988) comb, n., Procamallanus (Spiracamallanus) sp., Ruphidascaris (Sprentascaris) mahnerti (Petter et Cassone, 1984). Larvae: Anisakidae gen. sp., Brevimullicaecum sp., Ctmtracaecum sp. Type 1, Contracaecum sp. Type 2, Contracaecum sp. Type 3, Eustrongylides sp. All these parasites are reported from Venezuela for the first time and all findings represent new host records. Brevimulticae-cum larvae are reported from fishes for the first time. Almost all parasites are briefly described and illustrated and problems concerning their morphology, taxonomy, hosts and geographical distribution are discussed. A new name, Terranova diazungriai nom. nov. is proposed for T. caballeroi Diaz-Ungrfa, 1968 (a junior homonym of T. caballeroi Baruš et Coy Otero, 1966).