A new species of Rubiaceae from South Central Vietnam is described and illustrated. The new species, Mussaenda reflexisepala, is similar to M. caudatiloba in young plant parts densely white villose, but different in calyx lobes recurved, obviously reflexed, corolla lobes yelllow to orange or reddish orange, ovate to broadly obovate, which are clearly distinguished from other known species of Mussaenda. The pollen morphology of Mussaenda reflexisepala is also reported.