BACKGROUND: Studies report that survival outcomes in patients with non-muscle-invasive bladder cancer (NMIBC) are worse when cystectomy is delayed. However, no systematic evidence is available. OBJECTIVE: The aim of this study was to systematically review the literature to compare the long-term survival outcomes of patients with high-grade NMIBC (T1G3, including carcinoma in situ) who have early cystectomy compared to deferred radical cystectomy post-diagnosis. MATERIALS AND METHODS: A systematic review was carried out by searching MEDLINE and related databases (Google Scholar, National Health Service Evidence) for all relevant studies published from 1946 to present. Additional studies were identified through following the references of relevant papers. Studies were included if they met the following criteria: inclusion of at least 30 patients having high-grade NMIBC, 2 groups treated with either early or deferred cystectomy with a clear temporal cut-off between groups and reported data on survival rate of at least 5 years. RESULTS: Literature was systematically reviewed, and 10 studies were included, totaling 1,516 patients who underwent either primary cystectomy or deferred cystectomy. It was found that patients who underwent early cystectomy show improved 5- to 10-year cancer-specific survival (relative risk = 0.81, p = 0.029) suggesting a significant survival benefit when compared to deferred cystectomy. CONCLUSIONS: This study provides systematically gathered evidence showing benefit of early cystectomy. Despite this result, radical cystectomy greatly impairs quality of life and represents overtreatment for a significant minority. This result highlights the importance of a decisive treatment plan to minimize treatment delay.