The taxonomic nomenclature of the branchiobdellidans is reviewed. This includes the higher rankings and the numerous generic names assigned during the first half of the 19th century, particularly the use of Branchiobdella for species of the marine leech, Branchellion. The current taxonomic situation is summarized to highlight where inconsistencies and omissions exist in the data. The class Branchiobdellae consists of one order, Branchiobdellida, with five families containing a total of 21 genera and 149 species. The binomia are given with any junior synonyms, and these are followed by the citation in which the rank was reduced to junior status. In addition, the valid taxon Sinodrilus heterorchis has been placed in incertae sedis until the entry point of the sperm ducts into the glandular atrium can be determined, two species are considered nomen inquirenda and three others nomen nudem.