This antelope species reaches a head trunk length of 140 cm and a shoulder height of 110 cm. The weight is 55 to 125 kg, with males being significantly larger and heavier than females.
Females and males can be distinguished mainly by their body coloration: While the much larger males are slate-gray in color and have helically twisted horns with a white tip, the females, like juveniles, are hornless and predominantly reddish-brown in color.
All animals have up to 18 narrow, white horizontal stripes. The males wear both a long, erectile mane that covers the spine and a belly mane hanging from the throat to the hind legs. This feature distinguishes them from most other antelope species. The bushy tail is white on the underside in both sexes.
Nyalas are common in Mozambique, Zimbabwe and the far northeast of South Africa. from where they also found their way to some hunting farms in Namibia. They prefer to live in dense bushes near water.
While females and juveniles form small herds, males are solitary animals. The nyalas feed mainly on foliage, but occasionally grasses are also eaten. One of the predators of the nyala is the leopard, but this has no significant effect on the population of this species.