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