A new specimen of Trogosus from the Akasaki Formation, Amakusa City in Kumamoto Prefecture, Japan, is represented by 12 teeth, mandibular fragments, and cervical vertebral remains of an old individual. This is the most informative specimen of Trogosus from Asia. Comparisons with all known species of Trogosus indicate that the specimen is comparable to the largest species, Trogosus latidens, which has been recorded only from the Bridgerian North American Land Mammal Age. In addition to few diagnostic features of T. latidens except for the large size, the poor preservation of the new specimen makes its taxonomic identification at the species level debatable. However, the presence of the Japanese Trogosus further supports the intercontinental diversity and distribution of the genus via Beringia.