Phylloporia, belonging to Hymenochaetaceae, Hymenochaetales, is a cosmopolitan genus; some species are plant pathogens and possess medicinal properties. The species diversity of Phylloporia has been extensively explored; however, there is still no known record available from certain regions. Phylloporia vietnamensis is described here, as a new species from Vietnam based on morphological and phylogenetic evidence. This is the first report of the genus Phylloporia in Vietnam. Phylloporia vietnamensis is characterized by annual, terrestrial, eccentrically stipitate basidiomes with small pores (9–11 per mm) and thick stipe (up to 1.5 cm in diam), a dimitic hyphal system in the upper tomentum, and the presence of cystidioles. Phylogenetically, P. vietnamensis occupied an independent lineage within the Phylloporia clade. This work will hopefully attract more attention to taxonomic works on Phylloporia in Vietnam.