Background/AimsVarious clinical scoring systems, including the Glasgow-Blatchford score (GBS), Rockall risk score (RS), and AIMS65 score (AIMS65), have been validated to predict the clinical outcomes in patients with upper gastrointestinal bleeding (UGIB). We compared the performance of these three scoring systems in predicting clinical outcomes in patients with UGIB in Korea.Methods : We retrospectively evaluated 286 patients with UGIB who visited emergency department. The primary outcome was the need for clinical intervention (endoscopic, radiologic, or surgical) and blood transfusion.Results : The causes of UGIB were esophageal/gastric varices in 64 patients, peptic ulcer in 168, Mallory-Weiss tear in 32, malignancy of UGI tract in eight, and unknown in 14. One hundred seventy-four (61%) patients required blood transfusion, 166 (58%) required endoscopic intervention, and 10 (3.5%) required surgical intervention. The GBS outperformed the RS and AIMS65 in predicting the need for endoscopic intervention.Conclusion : sThe GBS and RS were more accurate than AIMS65 in predicting the need for clinical interventions and transfusion patients with UGIB, regardless of variceal or nonvariceal bleeding. The AIMS65 may not be optimal for predicting clinical outcomes of UGIB in Korea.