Six new species of bucephalid trematodes from the prosorhynchine bucephalid genera Prosorhynchus Odhner, 1905 and Neidhartia Nagaty, 1937 are reported from the epinepheline genera Cephalopholis, Cromileptes, Epinephelus and Variola on the Great Barrier Reef, Australia. Two species of Prosorhynchus and one of Neidhartia are reported from Epinephelus spp., P. jexi n. sp. from E. quoyanus, P. lafii n. sp. from E. fuscoguttatus and N. epinepheli n. sp. from E. maculatus. The other three new species are P. robertsthomsoni n. sp. from Cephalopholis argus, C. cyanostigma and C. miniata, P. conorjonesi n. sp. from Cromileptes altivelis, and P. milleri n. sp. from Variola louti. Extensive examinations of other piscivorous fish species from the Great Barrier Reef have not revealed these six bucephalid species, which appear to be restricted at least to the host genera from which they are reported here.