Background and objective: Hedranthera barteri (HB) is used in folk medicine as a vermifuge, laxative and an anti-inflammatory agent. The aim of this study was to evaluate the anti-ulcer and antioxidant properties of the dichloromethane fraction of HB root (DMHBR).Methods: Anti-ulcerogenic activity was assessed in cold-restraint (CRU), aspirin (ASP), alcohol (AL), pyloric ligation (PL) induced gastric ulcer models in rats and histamine-induced duodenal ulcer (HST) in guinea pigs[1]. The effect of DMHBR (100 mg/kg) on gastric juice for free and total acidity, peptic activity and mucin secretion, using the pylorus ligated model, were evaluated. Chloral hydrate anaesthesia (300mg/kg), histamine acid phosphate (0.25 mg/kg) and promethazine hydrochloride (2.5 mg/kg) were administered intraperitoneally. All other drugs and samples were administered orally. The H+,K+-ATPase activity was assayed in gastric microsomes, spectrophotometrically. The in vitro anti-oxidant assays were explored through DPPH, nitric oxide, hydroxyl radical, superoxide anion scavenging assays. The procedures were done by avoiding stress.Results: DMHBR reduced the incidence of ulcers in CRU (63.3%), PL (58.5%), ASP (52.7%), HST (75.0%) and AL (53.87%). Also, reductions were observed in the free acidity (49.4%), total acidity (45.8%) and peptic activity (32.9%) with increase in the mucin secretion by 81.6 per cent. DMHBR (60-100 μg/ml) inhibited the Hydrogen, Potassium-adenosine triphosphatase (H+,K+-ATPase) activity with IC50 of 89.64 μg/ml compared with omeprazole (10-50 μg/ml ) with IC50 of 32.26 μg/ml. DMHBR showed antioxidant activity with IC50 values of DPPH (397.69 μg/ml), nitric oxide (475.88 μg/ml), hydroxyl radical (244.22 μg/ml) and superoxide anion radical (285.20 μg/ml).Interpretation and Conclusion: DMHBR showed anti-ulcer activity against experimentally-induced peptic ulcer models and exhibited both cytoprotective and anti-secretory property. It exhibited a proton pump inhibition activity and its anti-ulcer properties may be partly ascribed to its antioxidant activities.Key words Antioxidant – H+, K+-ATPase, Hedranthera barteri, omeprazole, peptic ulcer.