Background: Recently, a new international bleeding score was developed to predict 30-day hospital mortality in patients with upper gastrointestinal bleeding (UGIB). However, the efficacy of this newly developed scoring system has not been extensively investigated. We aimed to validate a new scoring system for predicting 30-day mortality in patients with non-variceal UGIB and determine whether a higher score is associated with re-bleeding, length of hospital stay, and endoscopic failure. Methods: A retrospective study was performed on 905 patients with acute non-variceal UGIB who were examined in our hospital between January 2013 and December 2017. Baseline characteristics, endoscopic findings, rebleeding, admission, and mortality were reviewed. The 30-day mortality rate of the new international bleeding risk score was calculated using the receiver operating characteristic curves and compared to the pre-endoscopy Rockall score, AIMS65, Glasgow Blatchford score, and Progetto Nazionale Emorragia Digestiva score. To verify the variable for the 30-day mortality of the new scoring system, we performed multivariate logistic regression using our data and further analyzed the score items. Results: The new international bleeding scoring system showed higher receiver operating characteristic (ROC) curve values in predicting mortality (area under ROC curve 0.958; [95% confidence interval (CI)]), compared with such as AIMS65 (