Greater kudus have a narrow body with long legs, and their coats can range from brown/bluish-grey to reddish-brown. They possess between 4–12 vertical white stripes along their torso. The head tends to be darker in colour than the rest of the body, and exhibits a small white chevron which runs between the eyes.

Male greater kudus tend to be much larger than the females, and vocalize much more, utilizing low grunts, clucks, humming, and gasping. The males also have large manes running along their throats, and large horns with two and a half twists, which, were they to be straightened, would reach an average length of 120 cm (47 in), with the record being 187.64 cm (73.87 in). They diverge slightly as they slant back from the head. The horns do not begin to grow until the male is between the age of 6–12 months, twisting once at around 2 years of age, and not reaching the full two and a half twists until they are 6 years old; occasionally they may even have 3 full turns.

Males weigh 190–270 kg (420–600 lb), with a maximum of 315 kg (690 lb), and stand about 180 cm (71 in) tall at the shoulder. The body length is 185–245 cm (6.07–8.04 ft). The tail is 30–55 cm (12–22 in) long. The ears of the greater kudu are large and round. Females weigh 120–210 kg (260–460 lb) and on average stand 120 cm (47 in) tall at the shoulder; they are hornless, without a beard or nose markings.