Purpose To compare clinical outcome and quality of life (QoL) in octogenarian patients with muscle-invasive urothelial carcinoma (MIBC) either treated by radical cystectomy (RC) or transurethral resection of the tumor (TURBT). Methods We identified octogenarian patients with MIBC in our institutions since 2005. Clinical treatment outcomes and QoL were analyzed. Uni- and multivariable Cox regression analyses, two-tailed Wilcoxon test, Mann–Whitney test and Fisher’s exact test were assessed as appropriate. QoL was evaluated using FACT-G (Functional Assessment of Cancer Therapy-General) questionnaire. Results 143 patients were identified (RC: 51 cases, TURBT: 92 cases). Mean follow-up was 14 months (0–100 months). Median overall survival (OS) was 12 months in the RC group and 7 months in the TURBT group. TURBT and low preoperative hemoglobin were independent risk factors for reduced cancer-specific survival (CSS) (TURBT: p = 0.019, Hb: p = 0.008) and OS (TURBT: p = 0.026, Hb: p = 0.013) in multivariable analyses. Baseline QoL was low throughout the whole cohort. There was no difference in baseline FACT-G scoring comparing RC and TURBT (FACT-G total score (median): RC 43.7/108 vs. TURBT 44.0/108, p = 0.7144). Increased FACT-G questionnaire scoring was assessed for RC patients (median percentage score change RC 22.9%, TURBT 2.3%, p < 0.0001). Conclusion RC and TURBT are feasible treatment options for MIBC in octogenarian patients. In our cohort, RC was associated with increased CSS, OS and QoL. QoL in general was low throughout the whole cohort. Interdisciplinary decision-making has to be improved for these critically ill patients.