Objective: The aim of the study was to evaluate the impact of the clinical significance of incidental prostate cancer (PC) on overall survival (OS) after radical cystoprostatectomy (RC) for bladder cancer (BC). Methods: A total of 822 consecutive men underwent RC in 3 academic centers between 1996 and 2011. The clinical significance of incidental PC was determined according to the Epstein criteria. The Kaplan-Meier analysis with log-rank was used to investigate the impact of PC on OS and univariate and multivariate Cox regression analyses for risk factors of OS. The median follow-up was 36 months (interquartile range 10-49). Results: Of the 822 men, 117 (14.2%) had clinically significant, 243 (29.6%) insignificant and 462 (56.2) no PC at RC. Men with PC were at higher risk for lymphovascular invasion (LVI) of BC compared to men without PC (p < 0.001). The 5-year OS for men with clinically significant, insignificant and no PC was 33.3, 51.3 and 51.5%, respectively (p = 0.050). In the subgroup of pN0 patients (n = 601), clinically significant PC was significantly associated with inferior OS (p = 0.044) but not in multivariable analysis (p = 0.46). Conclusions: We did not find the clinical significance of incidental PC to be an independent predictor. However, the positive correlation between incidental PC and LVI of BC deserves further investigation.