Plankton samples were collected fortnightly off São Paulo coast during 1958, 1959 and 1960. The following Thaliacians were recorded Doliolum nationalis, Dolioletta gegenbauri and Thalia democrática. Morphological and ecological aspects of each species were studied. Doliolids seemed to be endemic in the region, occurring throughout the whole period of survey. The salps occurred only occasionally in dense swarms suggesting that this species is carried into the region by offshore waters.