Introduction The aim of this study was to compare overall survival in elderly patients (≥ 80 years) with muscle-invasive bladder cancer (MIBC) undergoing either radical cystectomy (RC) or conservative treatment. Material and Methods We performed a retrospective, comparative analysis of overall- and cancer-specific survival in octagenarians with MIBC (≥ pT2) submitted to RC or conservative treatment. Uni- and multivariable Cox regression analysis were performed to assess predictors of overall survival. Cumulative hospital stay was also analyzed for all patients. Results The RC-group consisted of 33 patients with a mean age of 82.3 years (IQR 80.4-85.4 years) and the bladder preservation a cohort of 35 patients aged 83.8 years (IQR 81.8-88.2 years). No difference was detectable for overall survival (15.9 months versus 9.5 months; p = 0.18) and cancer-specific survival (23.5 months versus 19.5 months p = 0.71) or 90-day mortality (6.1% versus 14.3%; p = 0.43) between the two groups. Patients who received conservative treatment had a shorter cumulative length of hospital stay (p = 0.001). Age at the time of transurethral resection of the bladder (TUR-B) was an independent predictor of the overall survival (p = 0.004). Conclusions In this retrospective study, no clear survival benefit was observed for patients ≥ 80 years submitted either to radical cystectomy or conservative treatment. There was however a trend favoring radical cystectomy but this did not approach statistical significance. Octagenarians that underwent RC however spent more of their remaining lifetime in the hospital than those treated conservatively.