Antiulcer activity of seeds of Moringa Oleifera was studied in rats in which gastric ulcers were induced by oral administration of ethanol and pylorus ligation. Seeds extract of Moringa Oleifera was administered in the dose of 150 and 200 mg/kg orally. The antiulcer activity was assessed by determining and comparing the ulcer index in the test group with that of the vehicle control group. Gastric fluid total acidity and free acidity were estimated in pylorus ligated rats. Omeprazol was used as a reference drug. The results suggested that ethanolic extract of Moringa Oleifera possesses significant antiulcer activity.