Ischaemia and reperfusion are known to induce gastric lesions, predominantly due to excessive formation of reactive oxygen metabolites, adhesion of neutrophils to endothelial cells, microvascular dysfunction, gastric acid secretion, endogenous histamine and gastrin release. We have studied the effect of (+)-catechin on a gastric ulcer model involving damage to gastric injury by ischaemia- reperfusion (I/R) in rats. (+)-Catechin 50 mg kg(-1)administered orally, once daily for three days after the initiation of I/R injury showed a significant (P<0.001) anti-ulcer activity against mucosal dam- age. However, (+)-catechin significantly decreased the lipid peroxidation and increased the level of catalase in the I/R condition. Elevated levels of alkaline phosphatase in the I/R group was significantly lowered (P<0.01) by (+)-catechin. The amount of H(+)K(+)ATPase was significantly decreased (P<0.001) in (+)-catechin-treated as compared with I/R rats. (+)-Catechin significantly decreased elevated plasma histamine (P<0.05) and corticosterone (P<0.05). The results suggested that (+)-catechin protected gastric mucosa against ischaemia-reperfusion-induced gastric ulcers by its antioxidant activity and mucus protection.