The present study provides a checklist of the polychaete fauna collected on the continental shelf off Aveiro (NW Portugal), within an area located between latitudes 40°30’N and 40°50’N and longitudes 8°40’W and 9°20’W, and a depth range of 8 to 185 m. The list includes 136 species, belonging to 37 families, from which 19 are new records for the Portuguese coast (Isolda pulchella, Mesochaetopterus sagittarius, Aphelochaeta multibranchis, Chaetozone cf. vivipara, Diplocirrus hirsutus, Goniadella gracilis, Gyptis mediterranea, Lumbrinerides crassicephala, Eumida bahusiensis, Eumida ockelmanni, Nereiphylla paretti, Phyllodoce rosea, Glyphohesione klatti, Malmgreniella arenicolae, Prionospio aluta, Pseudopolydora paucibranchisata, Pseudopolydora pulchra, Scolelepis mesnili, Polycirrus cf. medusa). The shelf off Aveiro presents a well- defined pattern of sediment distribution, with finer sand on the inner (8–22 m depth) and the outer (94–184 m depth) parts of the shelf and coarser sediments on the mid-shelf. The distribution of polychaete assemblages follows closely the aforementioned sedimentary pattern, showing different specific composition and structure in each of the three areas. Depth was also found to play an important role in the distribution of some polychaete species.