The role of palliative radiation treatment of prostate cancer is well recognized. Appreciation of the value of definitive radiation therapy in management of locally advanced prostate cancer is increasing. Optimal management requires careful patient selection with multidiscipline evaluation to provide accurate grading and staging, availability of adequate facilities, and careful planning the treatment. Definitive radiation therapy may be used as primary treatment, or in management of endocrine treatment failure, and in postoperative residual or recurrent cancers. Similar techniques may be employed in the management of locally symptomatic Stage D cancer. Definitive radiation therapy is useful management of some Stage B and many Stage C locally advanced and nonresectable cancers of the prostate.