A taxonomic revision of the Neotropical dioecious genus Lacunaria (Quiinaceae / Ochnaceae s. l.) is presented including keys to the species and subspecies, descriptions, illustrations, nomenclature, typification, and geographical distribution of each species. Seven species are recognized within the genus, one subspecies, L. jenmanii subsp. subsessilis, is described newly, and the status of Lacunaria decastyla has been changed, transferring it to Lacunaria crenata subsp. decastyla. Leaf pubescence, number of secondary veins, and petal, stamen, and carpel number, although all quite variable, are the most important characters to distinguish the species.