This is a stunning shrub or small, much-branched, evergreen tree that grows up to 3 m in height. The bark is smooth and pale brown. The leaves are ovate to almost circular and are crowded at the ends of the branches. The upper side of the leaf is grey-green to dark green and sparsely hairy, whereas the underside is pale green, heavily veined and densely hairy. The leaf margin is broadly scalloped and toothed, and usually slightly lobed.

Greyia flanaganii has showy, bright red, bell-shaped flowers in lax, few-flowered, downward-pointing racemes during spring (from August to October). Each flower is about 2 cm long with red stamens and style protruding from the mouth of the petal tube. The outer whorl of the stamens of this genus has lost its function of producing pollen and the stamens have been transformed into nectar glands. The nectar-rich flowers attract many insects such as honeybees, as well as pollinators like sunbirds. The fruits of this exciting shrub are 2.5 x 0.7 cm, brownish and cylindrical, and split along their inner surfaces to release the small seeds.