Pentasacme banaense Bo Li & T.S. Hoang, a new species of Apocynaceae discovered from Ba Na Nui Chua Nature Reserve of Danang City, Central Vietnam, is here described and illustrated. The new species is morphologically most similar to P. malipoense, but could be readily distinguished from the latter by the shape of leaves and corolla, the color of calyx, corolla and corolline corona, as well as the structure of staminal corona and style-head. Morphological description, high-resolution photographs, and habitat information of P. banaense plus a diagnostic key for all seven currently known species within the genus Pentasacme are provided.