A collection of 291 sipunculans from the continental shelf off southern Brazil is described. Ten species are included, two new to science (Phascolion medusae and Aspidosiphon longirhyncus). The latter comprises 74% of the specimens collected. Four are recorded for the first time in the southwestern Atlantic Oceccn (Golfingia eremita, G. pellucida, A. Albus, and A. exhaustus). The remaining two (G. misakiana and P. hedraeum) have been recorded from Brazilian waters before. While most of the material represents a warm, shallow water community (the southern end of the South Brazilian Province), another group of species found south of 34ºS in deepercooler water points to the possibility of a zoogeographical barrier on the continental slope in these latitudes.