A guide to European terrestrial and freshwater enchytraeid species is presented, designed for the identification of living specimens. Altogether 206 species are included. Recent taxonomic advances regarding new species, revisions, and improved standards of description are integrated. Marine and exotic species are excluded. The illustrated keys are preceded by introductions into the taxonomic traits, the general anatomy of enchytraeids, and the technique of handling living worms during the identification process. Due to persistent taxonomic problems in many groups, a 'sensu lato' approach is adopted in the circumscription of several common species. Bryodrilus ehlersi glandulosus Dózsa-Farkas, 1990 and Enchytraeus christenseni bisetosus Rota & Healy, 1994 are elevated to species rank; the latter receives a new name, Enchytraeus dichaetus, due to homonymy with Enchytraeus bisetosus Levinsen, 1884, now Fridericia bisetosa. Marionina libra Nielsen & Christensen, 1959 is transferred to Bryodrilus. Marionina serbui Botea, 1984 is synonymised with Buchholzia simplex Nielsen & Christensen, 1963. Mesenchytraeus franzi Nurminen, 1977, Euenchytraeus bisetosus Bretscher, 1906 and Cognettia clarae Bauer, 1993 are probably one species. The youngest name is maintained here, pending a systematic revision of the group. The purpose of this key is to facilitate and to stimulate work with enchytraeids.