Reinvestigation of the MeOH-CH(2)Cl(2) extract of the aerial parts of Cleome amblyocarpa led to isolation of a new dammarane triterpenoid, 15alpha-acetoxycleomblynol A, whose structure was determined to be 11alpha,15alpha-diacetoxybrachycarpon-22(23)-ene (1) by NMR data interpretation and X-ray analysis.