Acute upper gastrointestinal bleeding is a common reason for hospitalization. Mortality rates range from 5% to 15%; patients with severe comorbidities and those with persistent or recurrent bleeding are at highest risk. Accurate preliminary risk assessment and resuscitation can proceed simultaneously at initial presentation. Risk assessment can guide treatment decisions. Early upper gastrointestinal endoscopy, a cornerstone of management, allows for rapid diagnosis, application of endoscopic therapy, and completion of risk assessment. Endoscopic therapy can alter the natural history of upper gastrointestinal bleeding by reducing rates of further bleeding and, consequently, mortality. Complete risk assessment of both clinical and endoscopic factors can likely result in shorter hospital stays and improved outcomes. Early assessment helps identify low-risk patients in whom discharge on the day of presentation is appropriate.