multicenter open-labelled study was conducted in 286 patients with acute benign gastric ulcer in order to evaluate the safety and efficacy of nizatidine 300 mg given at bedtime. Endoscopy was performed on entry, at 4 weeks and, if the ulcer had not healed, at 8 weeks. Seven patients dropped out (four withdrawals due to adverse drug events and three lost to follow up). The endoscopic healing rates at 4 and 8 weeks were 53.8% and 86.7%, respectively. Age, sex, ulcer symptoms, alcohol consumption, smoking, ulcer location and duration of ulcer history were all found not to influence healing. Only the ulcer size significantly influenced the healing rate. The results of this trial confirmed the efficacy of a single dose of nizatidine at bedtime for 8 weeks in healing gastric ulcer.