The following three species of Philometra Costa, 1845 were recorded from the gonads of marine perciform fishes off the northeastern coast of the Mediterranean Sea (Iskenderun Bay), Turkey: P. lateolabracis (Yamaguti, 1935) from Epinephelus marginatus (Lowe, 1834) and Mycteroperca rubra (Bloch, 1793) (both Serranidae), P. filiformis (Stossich, 1896) from Pagellus erythrinus (Linnaeus, 1758) (Sparidae), and P. saltatrix Ramachandran, 1973 from Pomatomus saltatrix (Linnaeus, 1766) (Pomatomidae). New data on the morphology of all these histozoic parasites were obtained with the use of light and scanning electron microscopy, which made it possible to redescribe these so far little-known species. Males of P. lateolabracis were redescribed in detail on the basis of specimens recovered from M. rubra; conspecific mature females from the same host were described for the first time. Philometra saltatrix was found for the first time since its original description and for the first time outside North America. The finding of P. lateolabracis in M. rubra represents a new host record. The possible importance of these pathogenic parasites for cultures of marine perciform fishes is stressed. A key to Philometra spp. parasitic in the gonads of marine fishes is provided.