Summary The volatile oil obtained by hydrodistillation of air-dried samples of the leaf of Brachystegia eurycoma Harms, Caesalphinaceae, have been studied for their constituents by GC–MS. Oxygenated monoterpenoids (35.9%) and sesquiterpenoid hydrocarbons (30.7%) are the major class of compounds identified occurring in higher proportions. The main compounds of the leaf oil are 1,8-cineole (23.1%) and acorenone (10.0%). β-Caryophyllene (5.6%) and geranyl acetone (4.5%) are also present in significant amounts. This is first report on the constituents of the oil of the plants in the genus Brachystegia. The potential chemotherapeutic effects of the oil are discussed.