Xanthocercis zambesiaca is a large tree with a dense, rounded crown that usually reaches 30 m in height. Young twigs are pale yellowy brown, covered with short soft hair, and have a slightly zig-zagging growth pattern. Older branches are pale grey, with small, indistinct, grey lenticels. Bark is grey, at times quite dark in tone, and is rough, but does not peel off. It has a massive, cracked trunk, often composed of multiple stems buttressed together.

Leaves are compound, with about 7 pairs of leaflets, with a single leaf at the tip, alternate. Leaflets ovate with smooth margins and are dark green and shiny.

Flowers, pea-like, small, sweet-scented, white to cream-coloured, in hanging sprays, up to 100 mm long, at the end of the twigs, in spring and early summer (from September to December).

Fruits are grape-like, hanging downwards in clusters, smooth and shiny, yellowy green to yellow-brown when ripe, and there is a sharp spine at the top of each. Seeds are very dark brown, shiny, smooth, and shaped like 2 beans joined together.