Background: The gold standard treatment for localized muscle-invasive bladder cancer (MIBC) is neoadjuvant chemotherapy with radical cystectomy (RC). Guidelines suggest concurrent chemoradiation (CRT) could be considered as an alternative, and partial cystectomy (PC) may be considered in carefully selected individuals. The bladder preservation strategies are gaining popularity, and due to the concerns about morbidity associated with RC and limited life expectancy, the octogenarian population is exploring strategies that help preserve bladder function. Hence, it is crucial to understand the outcome of various bladder preservation strategies. Using the National Cancer Database (NCDB), we compared the overall survival (OS) of octogenarians treated with PC and CRT. Methods: We retrospectively evaluated the octogenarians with localized MIBC (cT2N0M0) <= 5 cm and urothelial histology between 2004 and 2018. Our analytic cohorts were the PC cohort, which included patients who underwent PC, and the CRT cohort, which included patients who received chemotherapy and radiotherapy within a 90-day timeframe. After propensity-matching with race and ethnicity, gender, facility type, median income, comorbidity index, and tumor grade, we compared the OS between PC and CRT cohorts. Results: A total of 1,038 were octogenarians who met our selection criteria. Among them, 248 (23.8%) underwent PC, and 790 (76.2%) received CRT. In the PC cohort, tumors were located predominantly in the dome (34.3%) and anterior wall (10.5%), while in the CRT cohort, tumors were in the trigone (8.4%), lateral (22.0%) and posterior walls (10.6%). The median OS for the matched PC and CRT cohort was 38.3 and 32.9 months, respectively (P=0.66). Multivariate Cox regression showed no difference in survival hazards between PC and CRT [hazard ratio =1.07 (95% confidence interval: 0.82-1.39)] (P=0.63). Conclusions: Our study comparing PC and CRT in octogenarians with T2 <= 5 cm tumors showed that PC had comparable OS to CRT. Therefore, PC can be considered a viable option in carefully selected octogenarians.