The genus Octobranchus contains nine valid species: Octobranchus pacificus (Berkeley & Berkeley, 1954), O. antarcticus Monro, 1936, O. floriceps Kingston & Mackie, 1980, O. japonicus Hessle, 1917, O. lingulatus (Grube, 1863), O. longipes Blankensteyn & Lana, 1987, O. myunus Hutchings & Peart, 2000, O. phyllocomus Hartman, 1952 and O. sexlobatus Hartmann- Schröder & Rosenfeldt, 1989 with a wide world distribution (North Sea, Sea of Japan, Australia, Brazil, Mediterranean and Antarctica). The monophyly of Octobranchus is sustained by the presence of four pairs of gills from the second to the fifth segments, and for the presence of 16 thoracic setigers. Based in this presumed monophyly, a cladistic analysis was done to determine the phylogenetic relationships among the species. The analysis of the data generated 14 most parsimonious trees, whose consense allowed to recognize the following phylogenetic relationship (O. sexlobatus (O. floriceps (O. antarcticus (O. pacificus (O. phyllocomus ((O. japonicus, O. lingulatus) (O. longipes, O. myunus))))))).