The Asteroidea collected during the cruises of the R/V "Prof. W. Besnard" along the coast of Rio Grande do Sul (Brazil) from April 1968 to January 1972 were studied. Twenty-four species are reported from the continental shelf for the area between Torres (29ºS) and Chui (34ºS). Labidiaster radiosus Lutken, Luidia clathrata (Say), Marginaster pectinatus Perrier, Mediaster trindadensis Bernasconi, Sclerasterias subangulosa (Verrill) and Tosia parva (Perrier) are new records for the area; Luidia barbadensis Perrier and L. elegans Perrier are new records for Brazil and Pectinidiscus aliciae sp. n. constitutes the first record of the genus from the Americas and is compared with the other two known species of the genus: P. annae and P. sibogae. Ecological data and the geographic distribution for each species are given. Keys for identification are provided. The general hydrology of the area and the biogeography are discussed and correlations of asteroid abundance with two commercially important fish species are made.