Shallow-water polychaete fauna associated with benthic invertebrates in Nhatrang Bay, Vietnam was studied based on extensive sampling surveys performed from 1985 to 2012. As a result, 24 polychaete species belonging to four families were found. A check list of all these species including synonymies, list of material examined, extended diagnosis, taxonomic and ecological notes, and distribution is here presented. Most reports include
in situ colour photos of representative specimens. The vast majority of symbionts belong to Polynoidae (13 species), followed by Syllidae (5 species), Hesionidae (5 species), and Spionidae (1 species), which were associated with echinoderms (53.8%), cnidarians (23.0%), sponges (11.5%), crustaceans (7.7%), and other polychaetes (3.8%). The number of symbiotic polychaetes occurring in Vietnamese coastal waters is here increased from 10 up to 26 species. The Vietnamese fauna of symbiotic polychaetes differs considerably from the Australian one. However, further studies on poorly investigated or even overlooked hosts (e.g. sponges, octocorals, tube dwelling polychaetes, echinoids and ophiuroids) will certainly lead to an increase in our knowledge on the diversity of symbiotic polychaetes of Vietnam.