The methanolic extract of the leaves of C. mucronata was screened for anti-ulcer properties using animal models. On isolated guinea pig ileum the extract inhibited contractions evoked by acetylcholine, histamine and serotonin. The extract remarkably decreased the propulsive movement of gastrointestinal content. The extract exhibited significant anti-ulcer activity protecting rats from indomethacin, histamine and stress-induced ulcers. It inhibited the growth of both Gram-positive and Gram-negative microorganisms. The oral LD50 value of the extract in mice was estimated to be 8.5 +/- 0.35 g/kg. The results revealed that the plant C. mucronata has potential medicinal value as an anti-ulcer agent.