Family Aberrantidae Wolf, 1987
Family Acoetidae Kinberg, 1856
Family Acrocirridae K. Banse, 1969
Family Alciopidae Ehlers, 1864
Family Alvinellidae Desbruyères & Laubier, 1986
Family Ampharetidae Malmgren, 1865
Family Amphinomidae Savigny, 1818
Family Antonbruuniidae K. Fauchald, 1977
Family Aphroditidae Malmgren, 1867
Family Apistobranchidae Mesnil & Caullery, 1898
Family Archinomidae Kudenov, 1991
Family Arenicolidae Johnston, 1835
Family Calamyzidae Hartmann-Schröder, 1971
Family Capitellidae Grube, 1862
Family Chaetopteridae Malmgren, 1867
Family Chrysopetalidae E. Ehlers, 1864
Family Cirratulidae Ryckholt, 1851
Family Cossuridae Day, 1963
Family Ctenodrilidae Kennel, 1882
Family Diurodrilidae Kristensen & Niilonen, 1982
Family Dorvilleidae Chamberlin, 1919
Family Eulepethidae Chamberlin, 1919
Family Eunicidae Savigny, 1818
Family Euphrosinidae Williams, 1851
Family Fauveliopsidae Hartman, 1971
Family Flabelligeridae de Saint-Joseph, 1894
Family Flotidae G.N. Buzhinskaja, 1995 ex
Family Glyceridae Grube, 1850
Family Goniadidae Kinberg, 1866
Family Hartmaniellidae M. Imajima, 1977
Family Hesionidae Grube, 1850
Family Histriobdellidae Vaillant, 1890
Family Ichthyotomidae Eisig, 1906
Family Iphitimidae K. Fauchald, 1970 see Family Dorvilleidae Chamberlin, 1919
Family Isopilidae see Family Iospilidae Bergström, 1914
Family Lacydoniidae Bergström, 1914
Family Laetmonectidae
Family Levidoridae
Family Longosomatidae Hartman, 1944
Family Lopadorrhynchidae Claparède, 1868
Family Lumbrineridae Schmarda, 1865
Family Magelonidae Cunningham & Ramage, 1888
Family Maldanidae Malmgren, 1867 - bamboo worms
Family Myzostomidae
Family Nautiliniellidae Miura & Laubier, 1990
Family Nephtyidae Grube, 1850
Family Nereididae Johnston, 1865
Family Nerillidae Levinsen, 1883
Family Oenonidae Kinberg, 1865
Family Onuphidae Kinberg, 1865
Family Opheliidae Malmgren, 1867
Family Orbiniidae Hartman, 1942
Family Oweniidae Rioja, 1917
Family Paralacydoniidae Pettibone, 1963
Family Paraonidae Cerruti, 1909
Family Parergodrilidae Reisinger, 1960
Family Pectinariidae de Quatrefages, 1865
Family Pholoidae Kinberg, 1858
Family Phyllodocidae Ørsted, 1843
Family Pilargidae de Saint-Joseph, 1895
Family Pisionidae Ehlers, 1901
Family Poebiidae
Family Poecilochaetidae Hannerz, 1956
Family Polygordiidae Czerniavsky, 1881
Family Polynoidae Kinberg, 1856
Family Pontodoridae Bergström, 1914
Family Protodrilidae Czerniavsky, 1881
Family Protodriloidae Purschke & Jouin, 1988 see Family Protodriloididae Purschke & Jouin, 1988
Family Psammodrilidae Swedmark, 1953
Family Questidae O. Hartman, 1966
Family Sabellariidae Savigny, 1818
Family Sabellidae Malmgren, 1867
Family Saccocirridae Czerniavsky, 1881
Family Scalibrematidae
Family Serpulidae Savigny, 1818
Family Sigalionidae Kinberg, 1856
Family Sphaerodoridae Malmgren, 1867
Family Spintheridae Augener, 1913
Family Spionidae Grube, 1850
Family Spirorbidae (Chamberlin, 1919) Pillai, 1970
Family Sternaspidae Carus, 1863
Family Syllidae Grube, 1850
Family Terebellidae Grube, 1850
Family Tomopteridae Johnston, 1865
Family Trichobranchidae Malmgren, 1865 see Family Terebellidae Grube, 1850
Family Trochochaetidae Pettibone, 1963
Family Typhloscolecidae Uljanin, 1878
Family Uncispionidae Green, 1982
Family Yndolaciidae Støp-Bowitz, 1987