CONTEXT: Repeat transurethral resection (reTUR) is advocated as a fundamental step towards complete clearance and appropriate staging of T1 bladder cancer tumors. OBJECTIVE: To assess the impact of reTUR in T1 bladder cancer via a systematic review of the literature and meta-analysis of available data sets. EVIDENCE ACQUISITION: After definition of the population and of the outcome, a systematic search of English language articles in the literature from 1980 to 2016 was performed. The pooled prevalence of residual tumor and of upstaging at reTUR were assessed and computed using a random effects model to take into account heterogeneity showed by I(2) and Cochran's Q values. A sensitivity analysis was conducted to exclude excessive influence by a single study. EVIDENCE SYNTHESIS: Among the papers identified, 29 were selected. A total of 3566 and 2556 cases formed the study population for assessment of the prevalence of residual tumor and upstaging, respectively. The corresponding numbers for the subgroup with detrusor muscle involvement at the initial TUR were 1565 and 1187. The pooled prevalence was 0.56 (95% confidence interval [CI] 0.48-0.63) for residual tumor and 0.1 (95% CI 0.06-0.14) for upstaging to T2 at reTUR. The corresponding rates for the detrusor muscle subgroup were 0.47 (95% CI 0.33-0.62) and 0.1 (95% CI 0.06-0.14). The sensitivity analysis excluded an excessive influence of each of the studies examined. CONCLUSIONS: Pooled prevalence rates for residual tumor ( ∼ 50%) and upstaging to invasive disease (10%) at reTUR in T1 cases were high, and were stable among studies in different decades and for cases with detrusor muscle involvement at the initial TUR. Therefore, reTUR remains a fundamental procedure. PATIENT SUMMARY: Repeat transurethral resection after a diagnosis of stage T1 bladder cancer is recommended given the high risk of misallocation to the proper treatment.