Roan is one of the largest African antelopes, only exceeded in size by the African buffalo and Eland. It has a grey coat with black and white facial markings, very long, pointed ears that are tufted at tip and long horns that are strongly curved backwards. The female is similar to the male, but with smaller, less heavily ridged horns.

Roan is aggressive when fighting or wounded. Dominant cows have been documented leading the advance toward any oncoming threat. High shoulders, powerful necks and upstanding manes make roan formidable when defending their calves from attacks by spotted hyenas, leopards and wild dogs. With their backward curving, heavily ridged horns, they even threaten and deter lions.

The herd structure is matriarchal. Six to 20 females and young roan are led by a dominant cow who seeks grazing and resting places in regions with a low predator density. Young bulls stay in the herd for up to three years, then join and remain in bachelor herds until mature at age six, after which they walk alone and seek to breed.

Roan tolerates more open savannah and taller grass than sable. They are also more at home on floodplains and at higher elevations of up to 2 400 metres. Predominantly water-dependent grazers adapted to subsist on tufted perennial grasses growing on infertile soils, roan will only occasionally browse.