In poor light and thick bush, the two kudu species can be confused. The reliable marks are on the front of the animal. The lesser kudu shows two white chevrons or patches on the throat, one high and one lower on the chest, which the greater kudu lacks. It also carries more white body stripes, typically eleven to fifteen against six to ten in the greater kudu, and the greater kudu bull has a conspicuous fringe of hair along the throat that the lesser kudu does not.
Size differs clearly, though the gap is wider in mass than in height. A lesser kudu stands roughly ninety to one hundred and five centimetres at the shoulder and weighs sixty to one hundred kilograms; a greater kudu bull is about a third taller and two to three times heavier. The species also separate by habitat, with the lesser kudu preferring drier, denser thornbush.
The two are not each other's closest relatives despite the shared name. Genetic work places lesser kudu apart within the spiral-horned antelope group, so the naming reflects appearance rather than a sister-species relationship.