Background and Aim: Risk stratification for upper gastrointestinal bleeding (UGIB) is recommended. However, scoring system accuracy is suboptimal, and score calculation can be complex. Our aim was to develop a new score, the MAP(ASH) score, with information available in the emergency room and to validate it. Methods: The score was built from a prospective database of patients with UGIB and validated in an international database of 3012 patients from six hospitals. Outcomes were 30-day mortality, endoscopic intervention, any intervention (red blood transfusion, endoscopic treatment, interventional radiology, surgery, or death), and rebleeding. Accuracy to predict outcomes was assessed by the area under the receiver operating characteristic curve (AUROC). Results: Five hundred forty-seven patients were included in the development cohort. Impaired mental status, albumin 100, American Society of Anesthesiologists score > 2, systolic blood pressure