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 sharply. A lesser kudu stands around a metre at the shoulder and weighs roughly sixty to one hundred kilograms; a greater kudu bull can be twice that height class and several times the mass. 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.