The 1.80 m (6 ft) long creature would have superficially resembled an okapi or a deer. Unlike these, however, Prolibytherium displayed dramatic sexual dimorphism, in that the male had a set of large, leaf-shaped ossicones with a width of 35 cm (1 ft 2 in), while the female had a set of slender, horn-like ossicones.
The taxonomic status of Prolibytherium remains in flux. At one time, it was described as a relative of Sivatherium (as a precursor to "Libytherium maurusium" (S. maurusium). Later, it would be regarded as a palaeomerycid, or either as a climacoceratid, or as a basal member of Giraffoidea. With the discovery and study of a female skull in 2010, Prolibytherium is tentatively regarded as a climacoceratid.