Buddleja dysophylla is a scrambling shrub, occasionally a small tree, that grows up to about 3 m high. Branches are wide spreading, climbing and brittle, with pale brown bark and young growth is often densely hairy. The leaves are simple, broad, petiolate, triangular to ovate, 10–100 mm long and 7–75 mm wide, sparsely hairy on the upper surface and densely covered with greyish to cream or rusty brown hairs on the under surface, the margins irregularly scalloped or toothed.

The flowers are small, about 4 mm long, short-tubed with stamens protuding from the mouth, creamy-white, often with a reddish brown centre, sweetly-scented, and are borne in large, loose heads up to 200 mm wide, at the ends of branches, in autumn, winter and spring (from May to September). The fruit is a cylindrical capsule, about 5 mm long, covered with brownish hairs. The seeds pale brown, flattened, circular.