A polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP) technique was developed for the molecular identification of 2 introduced bucephalid trematodes, Prosorhynchoides ozakii and Parabucephalopsis parasiluri. The method was applied for sporocysts and cercariae obtained from the golden mussel Limnoperna fortunei collected in the Uji River, Japan. The PCR–RFLP method showed that L. fortunei is the intermediate host of both trematode species. The present study thus recognizes the risk of L. fortunei, an invasive molluscan species, as a potential host for pathogenic trematodes.