The present report deals with several western Atlantic species of the snapping shrimp genus Synalpheus Spence Bate, 1888 occurring in Brazilian territorial waters. Two species, Synalpheus cf. ruetzleri Macdonald & Duffy, 2006 and Synalpheus yano (Ríos & Duffy, 2007), are recorded from the southwestern Atlantic Ocean and Brazil (Ceará) for the first time; S. yano is also newly reported from the eastern Gulf of Mexico and USA (Florida). Synalpheus androsi Coutière, 1909, a distinctive species previously known in Brazil only from a single unconfirmed record, is confirmed to be present in Brazilian waters based on material from Bahia and Espírito Santo. Synalpheus tenuispina Coutière, 1909, a poorly known species from southern Brazil, is redescribed. Synalpheus ul (Ríos & Duffy, 2007), previously known from Bahia and Alagoas, is reported from Pernambuco based on older "Calypso" material misidentified as Synalpheus longicarpus (Herrick, 1891). A new species from the Synalpheus paraneptunus Coutière, 1909 complex is described as Synalpheus maxillispinus sp. nov. based on three specimens dredged from moderate depths (15-55 m) off southern Bahia and Espírito Santo, eastern Brazil. Finally, an incomplete specimen that appears to belong to a species presently unknown in Brazil is preliminarily reported as Synalpheus sp. gambarelloides group. Illustrations are provided for all reported taxa except for S. ul.