AIM: To validate the Rockall scoring system for predicting outcomes of rebleeding, and the need for a surgical procedure and death. METHODS: We used data extracted from the Registry of Upper Gastrointestinal Bleeding and Endoscopy including information of 1869 patients with non-variceal upper gastrointestinal bleeding treated in Canadian hospitals. Risk scores were calculated and used to classify patients based on outcomes. For each outcome, we used χ2 goodness-of-fit tests to assess the degree of calibration, and built receiver operating characteristic curves and calculated the area under the curve (AUC) to evaluate the discriminative ability of the scoring system. RESULTS: For rebleeding, the χ2 goodness-of-fit test indicated an acceptable fit for the model [χ2 (8) = 12.83, P = 0.12]. For surgical procedures [χ2 (8) = 5.3, P = 0.73] and death [χ2 (8) = 3.78, P = 0.88], the tests showed solid correspondence between observed proportions and predicted probabilities. The AUC was 0.59 (95% CI: 0.55-0.62) for the outcome of rebleeding and 0.60 (95% CI: 0.54-0.67) for surgical procedures, representing apoor discriminative ability of the scoring system. For the outcome of death, the AUC was 0.73 (95% CI: 0.69-0.78), indicating an acceptable discriminative ability. CONCLUSION: The Rockall scoring system provides an acceptable tool to predict death, but performs poorly for endpoints of rebleeding and surgical procedures. METHODS: We used data extracted from the Registry of Upper Gastrointestinal Bleeding and Endoscopy including information of 1869 patients with non-variceal upper gastrointestinal For each outcome, we used χ2 goodness-of-fit tests to assess the degree of calibration, and built receiver operating characteristic curves and calculated the area under the curve (AUC) to evaluate the discriminative ability of the scoring system. RESULTS: For rebleeding, the χ2 goodness-of-fit test indicates an acceptable fit for the model [χ2 (8) = 12.83, P = 0.12] the tests showed that the solid correspondence between the observed proportions and predicted probabilities. The AUC was 0.5 (0.5) For the outcome of rebleeding and 0.60 (95% CI: 0.54-0.67) for surgical procedures, representing apoor discriminative ability of the scoring system. For the outcome of death, the AUC was 0.73 (95% CI: 0.55-0.62) 95% CI: 0.69-0.78), indicating an acceptable discriminative ability. CONCLUSION: The Rockall scoring system provides an acceptable tool to predict death, but performs poorly for endpoints of rebleeding and surgical procedures.