Abstract: Ethanol extract of Hibiscus aculeatus (HAE) was assessed in different acute and chronic gastric ulcer models in rats. HAE, 50-200 mg kg-1 administered orally, twice daily for 5 days showed dose-dependent ulcer protective effect in pylorus ligation (9.21-52.63% protection, p<0.05), aspirin (23.95-56.25% protection, p<0.05), ethanol (13.55-58.47% protection, p<0.05), cold-restraint stress (18.34-72.92% protection, p<0.05 to p<0.001) and acetic acid (p<0.05 to p<0.001) induced acute and chronic ulcers. HAE also significantly (p<0.001) reduced the ulcer incidence (40 and 10%) and severity (54.35 and 85.37% protection) of duodenal ulcer, induced by cysteamine. HAE offered protection (49.57 and 58.97%) against ethanol-induced depletion of gastric wall mucus. And also, HAE reduced the ulcer index with significant decrease in plasma corticosterone (21.15 and 33.51% protection, p<0.05), lipid peroxidation (16.66 and 38.88% protection, p<0.01 and p<0.001), superoxide dismutase (17.64 and 47.25% protection, p<0.05 and p<0.001) and an increase in catalase (25.84 and 83.14% protection, p<0.05 and p<0.001) activity respectively. Preliminary phytochemical screening of the HAE showed positive test for flavanoids, terpenoids, steroids, tannins and saponins. The results indicate that HAE possesses gastroprotective and antioxidant activity.