Locally invasive or T3 prostate cancer includes cases with intracapsular and extracapsular extension of tumor. For these men, adjuvant radiation therapy can improve long-term local control by eradicating microscopic tumor deposits in the prostatic bed, and may improve overall survival. Issues that generate debate include the timing of adjuvant radiation in relation to surgery, the volume to be treated, and techniques for minimizing morbidity. These issues will be discussed in this article.