Preliminary analysis was made of 76 species in the monotypic family Bipaliidae, for which the copulatory apparatus has been described. Four characters from the copulatory organs were selected: profile of the female organ (three character states), approachment of the ovovitelline ducts to the female organ (two states), shape of the penial papilla (two states), and shape of the male antrum wall (three states). Data were scored for five preliminary ingroup taxa, viz., the restricted genus Placocephalus, and four other a priori defined subgroups within the family, viz., the genus Bipalium sensu stricto and three other informal taxonomic groupings. An artificial outgroup taxon was constructed on the basis of character states generalized from the Geoplanidae subfamilies Caenoplaninae, Pelmatoplaninae and Rhynchodemidae subfamily Microplaninae. Analysis of the data matrix resulted in a single most parsimonious tree with the following topology: (outgroup (Placocephalus (Bipalium, group A (group B1, group B2)))).