Corchorus trilocularis is an erect, sparsely branched annual herb, growing up to 1 m tall. The stem is solid and cylindrical; the young branches are purplish and sparsely hairy. The leaves are simple, alternate, borne on short hairy stalks, and framed by two linear stipules. The leaf blade is oblong to lance-shaped, with a rounded base and a dentate margin. The first tooth at the base of the blade is occasionally enlarged and extended by a filament curving downward. Small pale yellow flowers are arranged in clusters opposite to the leaf stalks; petals and sepals are free and stamens numerous. The fruit is a linear capsule with angular cross-section, more or less erect; it is solitary or in groups of up to 3. At maturity, it splits open, releasing numerous small angular black seeds.