Campnosperma zacharyi Randrianasolo & Lowry, a distinctive new species from northeastern Madagascar, is described and illustrated. It differs from the four previously known Malagasy species of this dioecious genus by several striking foliar characters. The new species is known only from humid forests on the quartzite massif of Ankirindro NNW of the town of Maroantsetra, where it has been collected in both flower and fruit.