In the last two decades, many authors have treated prostatic carcinoma by radiation therapy. Accumulated data have been updated, after 10 and 15 years of follow-up. In stage A and B, the reported survival and local control rates after irradiation (20, 22, 30, 34, 35, 39, 42) are as good as in selected patients treated by radical prostatectomy (9, 18, 23). In stage C, the results after irradiation (20, 22, 30, 42) are better than after radical surgery (23, 43). However, patients are nonrandomly selected and the methods of statistical analysis differ. Therefore, a valid comparison cannot be made. The therapeutic ratio is determined by survival and local control, and also by therapy related complications. It is therefore of interest to find out from radiotherapy series if their incidence is related to the treatment technique. Unfortunately, relatively few studies accurately describe treatment technique and complications. Gastro-intestinal radiation injury becomes significant when the dose at the posterior rectal wall is 65-76 Gy and the length of the treated rectum is at least 10 cm. A hot spot of 80-84 Gy needs to be only 2 to 3 cm to increase the risk of late bowel stenosis. Genito-urinary complications are influenced by local extension of the tumor and by previous surgical manipulations. A dose at the prostatic area exceeding 70 Gy should be avoided, as it does not improve local control (22, 35) and apparently increases the risk of late urethral stricture and penile/scrotal edema (12, 39). The dose at the anterior bladder wall correlates with other types of genito-urinary complications. Therefore, the anterior bladder wall should not receive a dose higher than 65 Gy. Incidence of impaired potency after irradiation is usually 30 to 40%, which is much less than after radical surgery. As many data in the literature dealing with radiation treatment of the prostate are still inadequate a more standardized reporting is recommended to make comparison of effectiveness and side effects possible.