Gyalectidium setiferum Vězda & Sérus., a foliicolous lichen characterized by having some vertically oriented whitish translucent cilia surrounding a swollen greenish diahyphal mass, is reported as new to East Asia. It was collected from two localities on the lowlands of central Honshu in Japan where it grew on leaves of Aucuba japonica and Maesa japonica. The description with illustration based on the Japanese material is given. Gyalectidium setiferum has been included in this genus due to its morphological features even though no fertile specimen has been found so far. The monophyly of this species and its position in this genus were newly confirmed by the molecular phylogenetic analysis based on mtSSU and nrLSU. Key words: Conidia, conidiomata, diahyphae, distribution, hyphophore, lichenized fungi, mtSSU, nrLSU, photobiont.