The present study investigated the possible protective effect of tannins isolated from Lagerstroemia speciosa L. leaves against ethanol and cold stress induced gastric damage. In ethanol induced model, gastric damage was induced by ethanol, one hour after tannin administration by a single dose whereas in cold restraint stress model tannins were administered for seven days and were subjected to cold stress for 4 hours and animals were sacrificed and the stomachs were taken for biochemical and histopathological analysis. Nitric oxide scavenging activity and FRAP assay proved the in vitro antioxidant activity possessed by the tannins. The tannins isolated from L. speciosa were found to be very effective that it protects the mucosa by 72.48 % in ethanol induced model and 55.1% in cold restraint stress model by 50mg/kg. The severity of gastric lesions was markedly decreased by the administration of tannins in both models. Administration of tannins significantly increased both gastric mucous and protein contents. Tannins increased the GSH level and decreased lipid peroxidation dose dependently. It can be concluded that the protective effects of tannins in gastric mucosa are mediated atleast partially by upregulation of antioxidant system.