A new species, Aciconula tridentata sp. nov., is described from the Brazilian coast. The type material were collected from Praia de Suape, Cabo de Santo Agostinho, Pernambuco, Brazil. This new species differs from all its congeners in having the propodus palm of male gnathopod 2 bearing a 3-dentate projection. Additionally, A. tridentata sp. nov. can be distinguished from A. australiensis and A. miranda in lacking a setose hump proximally in article 1 of the peduncle of antenna 1; the outer plate of maxilliped reaching the end of palp article 1, and the female pereopod 4 is 3-articulate. A key to species of the genus is provided.
