The phylogenetic relationships of Euthelepus (Polychaeta: Terebellidae: Thelepodinae) were studied bymeans of a parsimony analysis of 40 external characters. The ingroup terminals included four species ofEuthelepus, and the outgroup included 14 species of eight Thelepodinae genera, three belonging to thesubfamily Terebellinae, one species of Trichobranchinae, and one species of Polycirrinae. Only two mostparsimonious cladograms were found. However, the analysis revealed a large number of homoplastic characterssupporting the thelepodin branches. The monophyly of the genus Euthelepus was not supported, andthe monophyly of the other thelepodin genera, as well as the entire subfamily, is questioned. The largenumber of homoplasies indicated by the analysis emphasizes the need to further evaluate these hypothesesby using additional characters. A re-classification based on phylogenetic results must be considered.