Polychaetes of 31 species from 17 families (Amphinomidae, Chrysopetalidae, Eunicidae, Glyceridae, Hesionidae, Iphionidae, Lumbrineridae, Maldanidae, Nereididae, Oenonidae, Phyllodocidae, Polynoidae, Sabellidae, Serpulidae, Syllidae, Terebellidae, Trichobranchidae) were studied from five locations around Abu Musa Island, the Persian Gulf. Perinereis iranica sp. nov. is described as a new species for the Persian Gulf. Perinereis iranica sp. nov. is most similar to members of the Perinereis cultrifera species complex, which are also found in the Persian Gulf, but can be most easily distinguished from them by the number, shape and arrangement of paragnaths in Areas V and VI. Perinereis camiguana is compared to members of the genus Pseudonereis, and found to resemble them closely, but until type specimens can be re-examined, we recommend treating this species as Nereidinae incertae sedis. Fifteen species, belonging to 13 genera: Eunice ‘sp_Abu Musa’, Marphysa ‘sp_Abu Musa’, Glycera cf. tesselata, Hesione splendida, Lumbrineris ‘sp_Abu Musa’, Notoproctus ‘sp_Abu Musa’, Nereis sp. cf. N. pelagica, Eteone ‘sp_Abu Musa’, Harmothoe liaoi, Potamilla ‘sp_Abu Musa’, Branchiosyllis cf. exilis, Trypanosyllis ‘sp. 1_Abu Musa’, Trypanosyllis ‘sp. 2_Abu Musa’, Terebella ‘sp_Abu Musa’, Terebellides cf. stroemi are reported for the first time from the Persian Gulf; nine species remain to be named formally. Three genera: Notoproctus, Eteone, Terebella are recorded for the first time from the Persian Gulf.