Objective To evaluate the predictive value of the preoperative HAS-BLED score in estimating clinically significant blood loss in the course of radical cystectomy. Materials and methods We retrospectively reviewed 176 patients who underwent radical cystectomy. Major hemorrhage was defined as a change in hemoglobin level (delta hemoglobin = preoperative hemoglobin level – postoperative hemoglobin level) of ≥4 g/dl, the need for blood transfusion to manage bleeding, or the necessity of early reintervention due to postoperative hemorrhage or related complications within 14 days. HAS-BLED scores were calculated preoperatively. Univariable and multivariable logistic regression analyses were performed to identify independent predictors. Receiver operating characteristic analysis was used to assess the discriminative ability of the HAS-BLED score. Results Major postoperative bleeding occurred in 22 patients (12.5%). Bleeding patients had significantly higher HAS-BLED scores compared to those without bleeding ( P < 0.001). Each 1-point increase in the HAS-BLED score tripled the odds of bleeding (odds ratio: 3.01, 95% confidence interval: 1.83–4.93). Multivariable analysis identified hypertension, renal or hepatic dysfunction, and a history of stroke as independent risk factors. Receiver operating characteristic analysis showed an area under the curve of 0.796, and the Youden-optimal cutoff was 2.5, corresponding to a clinical threshold of ≥3. In a subgroup of patients on anticoagulants ( n = 35), 40% experienced bleeding, and HAS-BLED remained predictive (odds ratio: 2.02, P = 0.045). Conclusion The HAS-BLED score effectively predicts clinically meaningful bleeding after radical cystectomy and may aid in preoperative risk stratification. A threshold of ≥3 appears suitable for identifying high-risk patients, particularly in those on anticoagulant therapy.