A new poroid wood-inhabiting fungal genus, Geliporus, is proposed based on morphological characters and molecular data. It is typified by G. exilisporus comb. nov. (Basionym: Inonotus exilisporus), and characterized by resupinate basidiomata darkening in potassium hydroxide, a monomitic hyphal system with simple-septate and hyaline to yellowish generative hyphae, and hyaline, thin-walled, and cylindrical to oblong-ellipsoid basidiospores. Results of phylogenetic analyses inferred from the 5.8S and nLSU rDNA sequences indicate that G. exilisporus belongs to the Phanerochaetaceae in Polyporales and is closely related to the genus of Hyphodermella.