We evaluated helminth parasitism in the alien frog, Polypedates leucomystax, on Ishigakijima and Iriomotejima, Yaeyama Islands, Okinawa, Japan. Among 12 helminth species observed, the parasitic oligochaete, Allodero sp., may have been introduced by this frog to Ishigakijima without spreading to Iriomotejima. Raillietnema rhacophori, a nematode commonly parasitic in P. leucomystax of Okinawajima and Miyakojima, was not observed. Seven helminth species, namely, Mesocoelium sp., Rhabdias sp., Strongyloides sp., Cosmocerca japonica, Meteterakis sp., Oswaldocruzia hoepplii, Oswaldocruzia japalurae, Pseudoacanthocephalus sp. were surmised to be acquired from the endemic anurans and/or saurians in the Yaeyama Islands. This frog also serves as a paratenic host for Physalopteridae sp., Dispharynx sp. and Centrorhynchus sp./spp., in which adults are parasites of birds or snakes.