Propalaeotherium was named by Paul Gervais. Its name means "before Palaeotherium". It was considered a member of Palaeotheriidae by Hooker (1986). A 2004 study found it to be an equid instead.
The species P. parvulum and P. messelensis have been assigned to the equid genus Eurohippus.
Propalaeotheres were small animals, ranging from 30–60 cm at the shoulder weighing just 10 kg (22 lb) They looked rather like very small tapirs. They had no hooves, having instead several small nail-like hooflets. They were herbivorous, and the amazingly well-preserved Messel fossils show that they ate berries, and leaf matter picked up from the forest floor.