Although parasites of the genus Trichinella have been collected from wild animals in Japan, they have never been studied at species level. Muscle larvae of Trichinella collected from a black bear (Ursus thibetanus japonicus) and from a raccoon dog (Nyctereutes procyonoides viverrinus) in Japan have been identified as Trichinella britovi by random amplified polymorphic DNA analysis. The presence of T. britovi in Japan shows that this parasite has a wide distribution in the Palaearctic region, from western Europe to eastern Asia, and that the isotherm -6 C in January could be considered its northern border.