The opposite leaves of Ecbolium glabratum have no stipules, consistent with the nature of plants belonging to the Acanthaceae family.

The grey-green leaves are smooth and leathery, ovate in shape with entire margins. Their tips are usually pointed, occasionally rounded and rarely notched; when pointed, sometimes even mucronate, i.e. a slight, bristly protrusion being present. The leaf base is slightly stem-clasping, thus sessile or stalkless.

The pale leaf midrib is conspicuous, the blade halves folding in very slightly along it. The few pairs of ascending lateral veins are less conspicuous but clearly visible in their lower straight parts near the leaf midrib. These veins curve in near the margins where they gradually disappear, all slightly prominent upon the lower leaf surfaces.

Leaf dimensions are about 6 cm by 3 cm (Pooley, 1998; Leistner, (Ed.), 2000; iSpot).