Pararotalia cananeiaensis, a new rotaliid species from modern shelf sediments of southern Brazil is described. This small species is well-represented along the southern coast of Brazil. It was recorded for the first time in the laguno-estuarine complex of Cananéia-Iguape in 1995. It had never been reported before, probably because it was confused with juveniles of Ammonia. Its distribution has been studied in Brazilian coastal and paralic environments from Cabo Frio (Rio de Janeiro state) near latitude 22°50′S, to Florianopolis (Santa Catarina state) near latitude 27°35′S. Very small tests of Pararotalia cananeiaensis are easily suspended in Brazilian high energy coastal environments and are transported inward by tidal currents. Their presence in the sedimentary record can be used to gauge the extent of the effects of this transport mechanism in the estuaries of southern Brazil.