Introduction: The study aimed to investigate oncological outcomes of patients with concomitant bladder cancer (BC) and urethral carcinoma. Methods: This is a multicenter series of 110 patients (74 men, 36 women) diagnosed with urethral carcinoma at 10 referral centers between 1993 and 2012. Kaplan Meier analysis was used to investigate the impact of BC on survival, and Cox regression multivariable analysis was performed to identify predictors of recurrence. Results: Synchronous BC was diagnosed in 13 (12%) patients, and the median follow-up was 21 months (interquartile range 4-48). Urethral cancers were of higher grade in patients with synchronous BC compared to patients with non-synchronous BC (p = 0.020). Patients with synchronous BC exhibited significantly inferior 3-year recurrence-free survival (RFS) compared to patients with non-synchronous BC (63.2 vs. 34.4%; p = 0.026). In multivariable analysis, inferior RFS was associated with clinically advanced nodal stage (p < 0.001), proximal tumor location (p < 0.001) and synchronous BC (p = 0.020). Conclusion: The synchronous presence of BC in patients diagnosed with urethral carcinoma has a significant adverse impact on RFS and should be an impetus for a multimodal approach. (C) 2016 5. Karger AG, Basel