Background: Upper gastrointestinal bleeding (UGIB) is defined as hemorrhage that involves the mouth to the duodenum proximal to the ligament of Treitz. Upper gastrointestinal bleeding (UGIB) is a major public health problem, its prevalence being around 150 per 100,000 adults per year. Objective: The aim of this study was to predict mortality in patients with acute upper gastrointestinal bleeding in the emergency room using AIMS65 and Glasgow-Blatchford scoring systems and to assess which scoring system (Blatchford or AIMS65) is more accurate in predicting mortality in AUGIB. Patients and methods: This was a retrospective cohort study that was conducted at Emergency Department, Faculty of Medicine, Mansoura University. The study was carried out on records of acute upper GIT bleeding patients. We enrolled in this study a total of 362 patients who matched with our inclusion criteria. The mean age was 55.21 years, 61.6% were males and the mean BMI   was 25.47 kg/m². Results: Blatchford score at cut off ≥ 13 and AIMS65 at ≥ 3 are valid in the prediction of mortality in patients with acute upper gastrointestinal bleeding in emergency room. AIMS65 ≥ 3 was more accurate (sensitivity of 77.78% and specificity of 84.88%) than Blatchford score (sensitivity of 55.56% and specificity of 71.51%) in the prediction of mortality in patients with acute upper gastrointestinal bleeding in emergency room. Conclusion: AIMS65 score was superior to Blatchford score in prediction of mortality in patients with acute upper gastrointestinal bleeding in emergency room. GIT cancer, re-bleeding and increase INR value are independent predictors of mortality in patients with acute upper gastrointestinal bleeding in emergency room.