Purpose Men with localized prostate cancer have various treatment options available in their management. The optimal approach is controversial and can be influenced by multiple factors. This study aimed to investigate the influence of geographic region on the selection of treatment for prostate cancer. Methods and Materials Using the National Cancer Database, we identified men diagnosed with localized prostate cancer between 2010 and 2014. The United States was divided into 11 regions per the American Cancer Society Divisions. The first course of treatment was recorded as radiation therapy (RT), radical prostatectomy (RP), or active surveillance (AS). The RT subgroup consisted of patients receiving all forms of RT, including external beam and brachytherapy, or RT plus androgen deprivation therapy. The RP subgroup consisted of patients receiving RP alone or combined with RT or androgen deprivation therapy. A χ 2 test was performed to assess the association between region and frequency of RT and RP. Results This study included 462,811 men with localized prostate cancer who were treated in the United States, of whom 63.46% underwent RP, 31.54% underwent RT, and 5.00% underwent AS. Significant regional differences in RP and RT were observed ( P ≤ .0001). RP was used most commonly in the Midwest (75.07%) and High Plains (73.37%) regions, whereas RP was least used in the South Atlantic (59.04%) region. Similarly, RT was used most commonly in South Atlantic (40.96%) and New England (38.98%) regions and least commonly in the Midwest (24.93%) region. AS was used most in the New England (7.27%) and Midwest (6.8%) regions and least used in the High Plains (2.57%) and Mid-South (2.84%) regions. Conclusions Regional differences exist in the United States with regard to the definitive treatment of localized prostate cancer. The etiology for these regional differences is likely multifactorial.