One hundred sixty-three fish from four natural ponds in Florida were examined for parasites. Of these, 40 were grass carp (Ctenopharyngodon idella), an exotic herbivorous fish which had been introduced for research as a possible biological control of aquatic vegetation. The remaining 123 fish included six native species (largemouth bass, Micropterus salmoides; bluegill, Lepomis macrochirus; golden shiner, Notemigonus crysoleucas; lake chubsucker, Erimyzon sucetta; brown bullhead, Ictalurus nebulosus; yellow bullhead, Ictalurus natalis). Parasite faunas of the native fishes and grass carp were compared. Identified were 37 species of parasites from the native fishes and one species from grass carp. No exotic parasites were observed in the grass carp, but the grass carp were infected by a native parasite of the phylum Pentastomida, Sebekia oxycephala.