Background: The best antisecretory treatment after endoscopic hemostasis in patients with ulcer bleeding is still in quest., Objectives: To compare pantoprazole and somatostatin continuous infusion after endoscopic hemostasis in patients with bleeding peptic ulcers., Patients and Methods: A total of 164 consecutive patients with a bleeding peptic ulcer, after successful endoscopic hemostasis, were randomly assigned to receive, double blindly, continuous IV infusion of pantoprazole 8 mg/h for 48 h after a bolus of 40 mg (group P) or somatostatin 250 microg/h for 48 h after a bolus of 250 microg (group-S). Twenty-four-hour pH-metry was performed in the last 30 patients in each group. Endoscopy was performed, in case of bleeding nonrecurrence, every 48 h until disappearance of stigmata., Results: Bleeding recurrence: group S 14 patients (17%) versus group P 4 (5%) (P=0.046). In multivariate analysis, bleeding recurrence was 4.57 (CI 1.31-15.91) times more frequent in group S (P=0.02). There was no difference in the need for surgery and mortality. Acid suppression over pH 6: group S 82.9% of the time versus group P 81.5% (P=0.97). Acid suppression over pH 6 for >85% of the time: group S 14 (47%) patients versus group P 17 (57%) (P=0.44). Disappearance of endoscopic stigmata after 48 h: group S 25/68 patients (37%) versus group P 72/78 (92%) (P<0.0001). No major side effects identified in either study group., Conclusions: In patients with a bleeding ulcer, after successful endoscopic hemostasis, despite equipotent acid suppression, pantoprazole continuous infusion was superior to somatostatin to prevent bleeding recurrence and quick disappearance of the endoscopic stigmata. Nevertheless, no differences were seen in the need for surgery and mortality.