This publication is a checklist summarizing information on the parasites of Vietnamese fishes contained in world literature dating from the earliest known record (Billet 1898) to the end of 2003. Information is presented in the form of parasite-host and host-parasite lists and contains 453 named species of parasites (not including 4 nomina nuda), distributed among the higher taxa as follows: Protozoa - 48, Myxozoa - 33, Digenea - 151, Monogenoidea - 112, Cestoda - 16, Nematoda - 53, Acanthocephala - 21, Hirudinea - 2, Branchiura - 3, Copepoda - 12 and Isopoda - 2. Many records of parasites not identified to species level are also included. The Parasite-Host List is organized on a taxonomic basis and provides information for each parasite species on the environment (freshwater, brackish water, marine), the location (site of infection) in or on its host(s), the species of host(s) infected, the known geographic distribution (by administrative division) in Viet Nam, and the published sources for each host and locality record. The Host-Parasite List is organized according to the taxonomy of the hosts, and includes, for each host, the English language and local (Vietnamese) common names, environment (freshwater, brackish water, marine), status in Viet Nam (native or exotic), and information on the known distribution in Viet Nam of the parasites. Both lists are accompanied by remarks and footnotes, as warranted, giving specific information on points of systematics, nomenclature, possible misidentifications, introductions, etc. Citations are included for all references, as well as parasite and host indices. The following new taxonomic combinations are made: Elongoparorchis siamensis (Oshmarin, 1965) n. comb.; Capillaria ariusi (Parukhin, 1989) n. comb., Falcaustra babei (Ky, 1971) n. comb. and Neocamallanus trichogasterae (Pearse, 1933) n. comb.

The parasite fauna of fishes of Viet Nam has received considerable attention, particularly by scientists of the former Soviet Union, in the marine environment, and by Vietnamese and Czech freshwater scientists. Nevertheless, parasites have been recorded from only about ten percent of the more than 1 300 species of marine and freshwater fish occurring in the waters of Viet Nam. Knowledge of freshwater fauna is hampered by a lack of descriptive work and by many probable misidentifications of parasites, due to the tendency of Vietnamese workers to report European species from the local fish fauna.