The scrawled filefish Aluterus scriptus (Osbeck) is widely distributed in the world's tropical/warm-temperate waters. We collected a juvenile (19.7cmTL) of A. scriptus with a hand net off Osaki-Kamijima Island in the Seto Inland Sea on July 31, 2008. Because juveniles of A. scriptus are known to be associated with drifting seaweed, and have already been recorded at Iyo Nada in the Seto Inland Sea, this suggests that A. scriptus is passively introduced into the sea through the Bungo Channel by the Kuroshio Current. Considering the lowest water temperature in the sea is ca. 10°C in winter, it appears impossible that such a tropical/warm-temperate fish could overwinter here. It is likely that A. scriptus was in the sea as part of an abortive migration along with other tropical fish juveniles. Because a strong poison (palytoxin) is present in the internal organs of this fish, it is important that we should not eat this fish.