<jats:p>The structure and absolute configuration of (-)-bukittinggine (1), the major alkaloid isolated from the leaves of Sapium baccatum ( Roxb.) Ridley ( Euphorbiaceae ) have been determined from the crystal structure of its hydrobromide. Diffractometer data at 295 K were refined by least-squares techniques to a residual of 0.040 (3150 'observed' reflections). Crystals of bukittinggine hydrobromide are orthorhombic, P212121, a 14.947(4), b 14.580(4), c 8.801(2)Ǻ, Z4.