Endoscopic therapy is effective in securing hemostasis for bleeding ulcers, but bleeding recurs in 10% to 30% of patients. Prospective identification of patients at increased risk for rebleeding is requisite to reducing rebleeding rates. We previously developed a three-component scoring system that identifies patients at increased risk for rebleeding. In the present study, we prospectively validated our scoring system. Forty-seven men ranging in age from 23 to 95 years in whom endoscopic therapy for bleeding ulcers was successful were studied. Patients with pre-endoscopy scores greater than 5 or postendoscopy scores greater than 10 were stratified as high-risk, and patients with pre-endoscopy scores of 5 or less and post-endoscopy scores of 10 or less as low-risk. Twenty-six patients were categorized as high-risk and 19 as low-risk. All patients were followed until discharged from the hospital. The rebleeding rate for high-risk patients was 31% (8 of 26), compared with 0 for low-risk patients (p < .05). We conclude that our scoring system accurately predicts patients at increased risk for rebleeding after successful endoscopic therapy of bleeding ulcers.