Early identification of patients at low risk for poor outcome after acute upper gastrointestinal hemorrhage would allow reduction of diagnostic and therapeutic interventions. We identified six early predictors of good outcome: age less than 75 years, no unstable comorbid illness, no ascites found on physical examination, normal prothrombin time, and, within an hour after presentation, systolic blood pressure of 100 mm Hg or greater and nasogastric aspirate free of fresh blood. Presence of all six predictors defined the low-risk population. Among 162 patients in the development and retrospective validation phases of our study, all 74 low-risk patients had good outcomes. A prospective validation study of 111 patients further established the accuracy of our predictive method; only two of 52 low-risk patients had poor outcomes. Application of our method should allow more selective management of patients with acute upper gastrointestinal hemorrhage.