Background:We conducted a two-center study to investigate the prognostic value of preoperative fibrinogen-albumin ratio (FAR) in patients undergoing radical cystectomy (RC). Methods: The clinical and survival data of 267 patients with bladder cancer (BCa) treated with RC were collected, of which 140 patients from Xuzhou Central Hospital were divided into training set and 127 patients from The Second Affiliated Hospital of Nantong University were divided into validation set. X-tile software was used to obtain the optimal cut-off values for preoperative platelet-to-lymphocyte ratio (PLR), neutrophil-to-lymphocyte ratio (NLR) and FAR. Receiver operating characteristic (ROC) curves were used to compare the predictive ability of PLR, NLR, FAR and modified Glasgow prognostic score (mGPS). Kaplan-Meier curves were used to assess overall survival (OS) and progression-free survival (PFS) of patients in different FAR groups. Univariate and multivariate Cox regression were used to assess patients' independent risk factors, and R software was used to construct prognostic nomograms. Results: In the training set, the optimal cut-off values for PLR, NLR and FAR were 76.76, 3.97 and 0.08, respectively. Both in the training and validation sets, FAR had better ability to predict OS and PFS than PLR and NLR, and patients in the higher FAR group had worse OS and PFS. In the multivariate Cox regression analysis, FAR was an independent risk factor for OS [hazard ratio (HR) 3.569, 95% confidence interval (CI): 1.015-12.546, P=0.047] and PFS [HR 5.071, P=0.014]. In addition, FAR-based prognostic nomograms had high predictive ability than TNM staging. Conclusion: Preoperative FAR is an independent prognostic factor for OS and PFS in BCa patients treated with RC, and a high FAR predicted a poor prognosis. In addition, a prognostic nomogram based on FAR can better predict individual survival.