Acute upper gastrointestinal (GI) hemorrhage is one of the commonest causes for hospitalization worldwide. Endoscopic therapy is effective in achieving primary hemostasis. The shift of management from the operating theater to the endoscopy suite has not changed the rate of mortality over the past 20 years. Several hypotheses are discussed that may account for the lack of improvement in the mortality resulting from bleeding peptic ulcer. One potential way to improve management is to identify those at risk for adverse outcomes, which may improve the initial triage, timing of primary endoscopic hemostasis, and postendoscopic management. Two adverse outcomes generally considered as significant for acute upper GI hemorrhage are rebleeding and mortality. Numerous clinical risk models have been developed to predict these outcomes, and this article reviews them.