A new basidiolichen species, Lepidostroma asianum (Agaricomycetes, Lepidostromatales, Lepidostromataceae), is described based on basidiomata collected from red clay in southwestern Japan. This is the first report of a species in the genus Lepidostroma from Asia. The species is characterized by producing pale orange to reddish-orange, cylindrical to slightly fusiform basidiomata that taper toward the apex and by cylindrical to suballantoid basidiospores measuring 7.0–10.0 × 3.5–5.0 μm. In addition, it is associated with a green alga and forms a film-like thallus. Lepidostroma asianum differs from all previously-described species in its unique combination of these characteristics. Phylogenetic analyses of partial nuclear large subunit and small subunit rRNA gene sequences also differentiated it from other species. The cultural features of a Lepidostroma species are also provided for the first time.