Verapamil at doses 5, 10, 20 and 40 mg/kg, intraperitoneally (ip) and 40 mg/kg, orally reduced incidence of ulceration by Pyloric-ligation. Similarly verapamil inhibited aspirin-induced ulceration at a dose 40 mg/kg, orally and ip. Effect of verapamil on gastric acid secretion was also studied. At low dose it increased acid secretion significantly (5 mg/kg, ip) and at high dose (40 mg kg, ip and orally) it significantly decreased volume of secretion. This indicates that reduction of acid secretion contributes little to the antiulcer activity of verapamil because antiulcer effect was seen even at doses which did not decrease acid secretion.