Major advances have been made in the definitive use of various forms of radiotherapy (RT) in the management of clinically localized prostate cancer (PCa). Despite tremendous gains, the radiation oncology community continues to struggle with several key questions. In general, the areas of controversy pertain to how to improve the therapeutic ratio of RT. Specifically, key issues include dose escalation; the relative benefit of alternative forms of RT (ie, brachytherapy and protons); target localization; the use, timing, and duration of androgen deprivation; and the need for pelvic nodal irradiation. Multiple efforts have been made to address each of these issues; however, there is no consensus on how to resolve them. This review is an evidence-based critique of the available treatment approaches considered for the optimal use of radiotherapy as definitive management of clinically localized PCa.