The benefit of routine repeat endoscopy after endoscopic hemostasis in the management of peptic ulcer bleeding is controversial. The aim of this Review is to evaluate the efficacy of second-look endoscopy by examining the evidence from published, randomized, clinical trials. Outcome measurements included recurrent bleeding, surgery, mortality, blood transfusion, and length of hospital stay. Studies were categorized into those in which endoscopy was performed with endoscopic injection or thermal coagulation. On the basis of existing evidence, second-look endoscopy with heater probe reduces the risk of recurrent bleeding, but has no effect on overall mortality or the need for surgery. Therefore, routine second-look endoscopy cannot be recommended. Selected high-risk patients may benefit from second-look endoscopy, but the use of high-dose intravenous PPIs may obviate the need for this procedure.