Background: We conducted a comparative survival analysis between primary androgen deprivation therapy (PADT) and radical prostatectomy (RP) based on nationwide Korean population data that included all patients with prostate cancer. Materials and Methods: This study enrolled 4,538 patients with prostate cancer from the National Health Insurance Service (NHIS) database linked with Korean Central Cancer Registry data who were treated with PADT or RP between January 1, 2007, and December 31, 2014. Kaplan-Meier and multivariate survival analyses stratified by stage (localized and locally advanced) and age (<75 and ≥75 years) were performed using a Cox proportional hazards model to evaluate treatment effects. Results: Among 18,403 patients from the NHIS database diagnosed with prostate cancer during the study period, 4,538 satisfied inclusion criteria and were included in the analyses. Of these, 3,136 and 1,402 patients underwent RP or received PADT, respectively. Risk of death was significantly increased for patients who received PADT compared with those who underwent RP in the propensity score–matched cohort. In subgroup analyses stratified by stage and age, in every subgroup, patients who received PADT had a significantly increased risk of death compared with those who underwent RP. In particular, a much greater risk was observed for patients with locally advanced prostate cancer. Conclusions: Based on a nationwide survival analysis of nonmetastatic prostate cancer, this study provides valuable clinical implications that favor RP over PDAT for treatment of Asian populations. However, the possibility that survival differences have been overestimated due to not accounting for potential confounding characteristics must be considered.