BACKGROUND After endoscopic treatment of bleeding peptic ulcer, a high-dose infusion of omeprazole substantially reduces the risk of recurrent bleeding. The role of oral proton pump inhibitors for these patients is uncertain. The purpose of the present study was to assess whether the use of oral esomeprazole would reduce the frequency of recurrent bleeding after endoscopic treatment of bleeding peptic ulcers. METHODS Patients with actively bleeding ulcers or ulcers with non-bleeding visible vessels were treated with an epinephrine injection followed by thermocoagulation. After hemostasis had been achieved, they were randomly assigned in a double-blind fashion to receive esomeprazole (40 mg p.o. twice daily for 3 days) or placebo. The outcome measures studied were recurrent bleeding, blood transfusion requirement, surgery and death. RESULTS A total of 70 patients were enrolled, 35 in each group. Bleeding recurred within 30 days in two patients (5.7%) in the esomeprazole group, as compared with three (8.6%) in the placebo group (P = 0.999). Blood transfusion requirement was 2.8 +/- 1.4 units in the esomeprazole group and 2.7 +/- 1.3 units in the placebo group (P = 0.761). Duration of hospitalization was 4.82 +/- 1.8 days in the esomeprazole group and 4.58 +/- 2.7 days in the placebo group (P = 0.792). No patients needed surgery for control of bleeding and no patients died in both groups. CONCLUSIONS After successful endoscopic treatment of bleeding peptic ulcer, oral use of esomeprazole might offer no additional benefit on the risk of recurrent bleeding.