The Syllidae subfamilies Eusyllinae, Anoplosyllinae and Autolytinae, as well as the incertae sedis genera (Aguado et al., 2012), were studied from samples collected in shallow water from fjords and channels in Chilean Patagonia. One new species Paraehlersia kawesqar sp. nov. is described. The genus Nudisyllis Knox & Cameron, 1970 is recorded for the first time for Chile, while the species Brachysyllis infuscata (Ehlers, 1901a) and Syllides japonica Imajima, 1966 are recorded for the first time for continental Chile. Finally, Syllides articulosa Ehlers, 1897 and Epigamia sp. are also reported. The majority of the species were found inside tubes of the polychaete worm Chaetopterus cf. variopedatus (Renier, 1804) – a new habitat for syllid polychaetes. This work is an important contribution to the knowledge of syllids in Chile and to the polychaete fauna of the Patagonian region generally.