The n-hexane soluble fraction of the ethanolic extract of the roots of the plant Trewia polycarpa yielded a rare triterpenoid of taraxarane series, 3ß-acetoxytaraxaren-14-en-28-oic acid (I) whose identity has been confirmed by spectroscopic studies. This is the second report on the isolation of I from nature and first from the genus Trewia. Compound I exhibited prolongation of prothrombin time and also showed mild antibacterial and antifungal activities.