Aim of the study Momordica charantia L. (Cucurbitaceae) commonly known as ‘bitter gourd’ is a multi purpose herb cultivated in different parts of the world for its edible fruits. The objective of the present study was to evaluate the effect of standardized methanolic extract of Momordica charantia L. fruits on gastric and duodenal ulcers. Materials and methods The effect was evaluated in acetic acid induced chronic gastric ulcer, pylorus ligation induced gastric ulcer, ethanol induced gastric ulcer, stress induced gastric ulcer, indomethacin induced gastric ulcer and cysteamine induced duodenal ulcer model. The extract was administered orally at two different doses of 100 mg/kg and 500 mg/kg. Results The healing of acetic acid induced gastric ulcer was increased by both doses of the extract. In pylorus-ligated rats, the extract showed significant decrease in ulcer index, total acidity, free acidity and pepsin content and an increase in gastric mucosal content. The extract also reduced the ulcer index in stress induced, ethanol induced and indomethacin induced gastric ulcers and cysteamine induced duodenal ulcer. Conclusion The methanolic extract of Momordica charantia L. fruit increases healing of gastric ulcer and also prevents development of gastric ulcers and duodenal ulcers in rats.