The simple leaves of Thunbergia alata are broadly ovate; heart-shaped with large basal lobes and rounded to bluntly pointed tip. The leaves grow opposite on winged stalks from 2 cm to 5 cm long. Their margins may be entire or toothed, here sparsely and unevenly.

Five veins emerge from the leaf-base, a few incurving lateral ones ascending from the central, biggest one or midrib. The veins are prominent on the lower surface.

Leaf size is 2 cm to 6,5 cm long and 2 cm to 5,5 cm wide (Pooley, 1998; Germishuizen and Fabian, 1982).