The origin and evolution of the eureptantic nemerteans is discussed from a biogeographic point of view. It is most likely that East Indian Ocean was part of the ancestral distribution of the Eureptantia. The area cladogram estimated by Brooks parsimony analysis (BPA) is to a high degree congruent with a vicariance explanation of the evolution of the Eureptantia and suggests an ancestral distribution concordant with the Tethys Sea. A general area cladogram based on a combined BPA analysis of eureptantic nemerteans and acanthuroid fishes is reconstructed and suggested as a hypothesis of the relationships between east Indian Ocean, west Indian Ocean, west Pacific Ocean, east Atlantic Ocean, west Atlantic Ocean, and the Mediterranean. This tree is compared with cladograms from the same areas based on other taxa.