This petite antelope stands only 350mm at the shoulders, and rams weigh only 5 kg. Ewes are slightly larger and weighs 5.4 Kg. Light-brown to chestnut coat, fading slightly at the flanks. White underparts and inner legs. They have broad, rounded ears, ashy-grey on the outside and pink inside.
Only the rams grow horns, which are short, straight, heavily ridged and smooth tipped. Of all African antelope, this species has the largest pre-orbital scent glands relative to body size.
Apart from being a very shy antelope, they are also rare. The Suni is primarily active during the evening and night, sleeping the rest of the day in a shady, sheltered area. These shy antelope have excellent camouflage, which they use to their advantage.
When danger starts to approach, the Suni freezes, remaining hidden until the threat is nearly on top of them, at which point it leaps up and dodges around bushes and shrubs, quickly vanishing into the undergrowth.
Males defend territories of about 3 hectares, scent-marking the boundaries with preorbital gland secretions. On the peripheries of each defended area may be individual or communal dung piles.
Each male generally associates with a single female, even if several others share his territory. Weak barking and sharp whistling have been reported.