In the management of patients with acute upper gastrointestinal bleeding from non-variceal causes, endoscopic treatment and acid suppression are now the standard of care. Current endoscopic treatment in the form of either thermo-coagulation or clipping to the bleeding arteries is highly efficacious in the stopping bleeding. Unfortunately in 5 to 10% of patients, bleeding cannot be controlled during index endoscopy or recurs after initial hemostasis. These patients are often elderly with significant co-morbidities. Their bleeding lesions are large eroding into major sub-serosal arteries. In the few who need surgical salvage, mortality increases to around 30%. The Over-the-scope-Clip (OTSC) is a device, which allows endoscopists to capture a large amount of tissue and compress on the bleeding artery. The OTSC also has a high retention rate. Recurrent bleeding with the use of standard hemo-clips can occur because of their low retention rate. We reported the use of OTSC with a high success rate in a case series of patients with refractory bleeding after standard endoscopic treatment. We have also used OTSC in the treatment of bleeding from pseudo-aneurysm arising from large eroded arteries in ulcer base. A multicenter randomized controlled trial that compares OTSC to standard endoscopic treatment in the endoscopic treatment of refractory bleeding lesions has just been completed. The use of OTSC has been shown to be superior in achieving hemostatic control and reducing further bleeding. In this proposed randomized controlled trial, we would test the hypothesis that the use of OTSC, when used as the first or primary treatment, is superior to standard treatment in achieving hemostasis and thereby improve patients' outcomes.