Lasianthus gialaiensis V. S. Dang, Vuong, Quan & Naiki, a new species from Kon Chu Rang Nature Reserve, Gia Lai Province, in the central highlands of Vietnam, is described and illustrated. It is morphologically similar to L. bokorensis, which was discovered in Bokor National Park, southern Cambodia, in the shape of the leaves, inflorescences and orange fruit, but differs in having shorter petioles, shorter stipules and calyx tubes, larger corolla, and green calyx. A vernacular name, ecological information and a table comparing it with L. bokorensis are also provided.