Peptic ulcer bleeding (PUB) is a common and life threatening condition. Intravenous infusion of high dose omeprazole (80mg as bolus followed by 8 mg/hr for 72 hours ie 652 mg/72 hrs) after endoscopic therapy resulted in greater reductions of re-bleeding than did placebo. Thus the above regime became our departmental protocol. However, there is some evidence that both high dose and a regular dose of omeprazole (40mg once a day followed by a saline infusion ie 120mg/72 hrs) would be equally effective. We calculated that high dose regimen is about S$ 500 more expensive. The aim of our study is to determine the equivalence of both regimes in preventing re-bleeding rate (primary end-point), surgery and mortality in PUB patients.