In this paper we describe and illustrate a new species of Simaba from the sandy coastal plains in northeastern Brazil, and discuss the controversial limits of the three sections proposed in the genus by Englerian classification. Simaba arenaria has a restricted distribution: it is known only from two small, somewhat disturbed areas, in restinga vegetation of Bahia and Sergipe states. The evaluation of its threatened status indicates that it is an endangered taxon, according to the IUCN Red List categories and criteria. We also provide novel data on the seedling of this species.