The purpose of this paper is to give a preliminary qualitative assessment of the soft bottom macrofauna of the Bay of Santos and adjacent areas. Sixty-three samples were taken by the 'Emilia' with grab and otter trawl gears. 149 different species of benthic animals were collected, of which 52 were polychaets, 26 lamellibranchs, 20 echinoderms, 17 crustaceans, 14 gastropods, 4 cnidarians and 16 belonging to other taxonomic categories. The most frequent species were the polychaets Audouinia tentaculata, Poecilochaetus australis, Onuphis quadricuspis, Owenia fusiformis, Telepus setosus and Telepsavus costarum. The gastropod Littoridina australis var. nana occurred in high densities in the samples collected in the inner part of the Santos channel. Ophiactis lymani was found to be the most widely distributed ophiuran in this region. The lamellibranchs Mesodesma inactroides, Tivela mactroides, Donax hanleyanus and the thalassinid Callianassa major are common in the sand beaches of the bay. In the mangrove region numerous decapods occurred of the following genera: Uca, Ucides, Aratus, Metasesarma, the "Maria mulata", crab Goniopsis cruentata, etc. Five different station groups and two more areas may be recognized in the region of the Bay of Santos and the homonimous channel.
