INTRODUCTION: To investigate the correlation between preoperative De Ritis ratio (aspartate transaminase (AST)/alanine transaminase (ALT)) and postoperative outcome in patients with urothelial cell carcinoma (UC) treated with radical cystectomy. MATERIALS AND METHODS: We analyzed the clinical and pathological data of 771 patients who underwent radical cystectomy for bladder UC. Patients were divided into two groups according to the optimal value of AST/ALT ratio. The effect of the AST/ALT ratio was analyzed using the Kaplan-Meier method and Cox regression hazard models for patients' cancer-specific survival (CSS), overall survival (OS), and recurrence-free survival (RFS). In addition, propensity score matching of 1 : 1 was performed between the two groups. RESULTS: Median follow-up was 84.0 (36-275) months. Mean age was 64.8 ± 10.0 years. According to the receiver operating characteristic (ROC) analysis, the optimal threshold of the AST/ALT ratio was 1.1. In Kaplan-Meier analyses, the high AST/ALT group showed worse outcomes in CSS and OS (all < 0.001). Also, RFS ( = 0.001) in the Cox regression models of clinical and pathological parameters was used to predict CSS, OS, and AST/ALT ratio (HR 2.15, 95% CI 1.23-3.73, = 0.007) and pathological T stage (HR 4.80, 95% CI 1.19-19.28, = 0.003). To predict OS and AST/ALT ratio (HR 2.05, 95% CI 1.65-2.56, < 0.001), pathological T stage (HR 2.96, 95% CI 0.57-17.09, = 0.037) and positive lymph node (HR 1.71, 95% CI 1.50-1.91, = 0.021) were determined as independent prognostic factors. CONCLUSION: Preoperative AST/ALT ratio could be an independent prognostic factor in patients with UC treated with radical cystectomy.