The ant genus Sphinctomyrmex has been represented in the Neotropical Region until now by a single species, S. stali , known only from sparse localities in southeastern Brazil. Two new neotropical species are herein described, S. marcoyi sp. n. and S. schoerederi sp. n. from workers collected in the Brazilian Amazon and Atlantic Forest, respectively. New records for Sphinctomyrmex stali are presented, and the species is redescribed together with discussions on its high morphological variation and the identity of its type specimen. A key for the neotropical Sphinctomyrmex workers, images of all species presently known, and a distribution map are supplied.