There are three subspecies in the family: the Amazon river dolphin, the Bolivian river dolphin (found in the Madeira River), and the Orinoco river dolphin (found in the Orinoco basin).

There is also a debate about whether the Araguaian river dolphin (found in the Tocantins basin) should be considered as the fourth subspecies. Some scientists deliberate whether all the above subspecies should rather not be considered separate species.