Adding chemotherapy to radical cystectomy (RC) may improve outcome. Neoadjuvant treatment is advocated by guidelines based on meta-analysis data but is severely underused in clinical practice. Adjuvant treatment of patients at risk could be an alternative. We analyzed a sample of 798 patients who underwent RC between 1993 and 2011 for high-risk superficial or muscle-invasive urothelial or undifferentiated bladder cancer, of which 23% received adjuvant cisplatin-based chemotherapy and %5 received neoadjuvant chemotherapy. The use of adjuvant chemotherapy was an independent predictor of decreased overall mortality (hazard ratio [HR]: 0.50; 95% confidence interval [CI], 0.38-0.66; p < 0.0001) and bladder cancer-specific mortality (HR: 0.71; 95% CI, 0.52-0.97; p = 0.0321), but it was not associated with competing mortality. Similar figures were obtained when analyzing the number of cisplatin-containing cycles administered or when restricting the analysis to patients with lymph node-positive or extravesical but lymph node-negative disease, suggesting a mortality-reducing treatment effect after adjusting for several patient- and tumor-related confounders. Future trials should directly compare the concepts of neoadjuvant and adjuvant application of chemotherapy in candidates for RC. Patient summary Adjuvant chemotherapy may decrease overall and bladder cancer-specific mortality after radical cystectomy (RC). Future trials should directly compare the concepts of neoadjuvant and adjuvant application of chemotherapy in candidates for RC.