External beam radiation therapy is an effective, well tolerated treatment modality for localized prostate cancer with a low rate of severe morbidity. In this retrospective analysis experience with 431 patients who have been treated with definitive radiation therapy with aim at cure is presented. Median follow-up time was 4 years (range 1-17 years). Treatment was administered with 45 mega Volt photons in all cases. Does between 60-70 Gray to the prostate and 45-50 Gray to the pelvic lymph nodes have been applied. Disease-free survival rates approaching 80% in 5 years and 53% in 10 years have been achieved for disease confined to the prostate as compared to 50% at 5 years and 27% at 10 years for extracapsular disease. The prognostic significance of various factors such as stage, grade, lymph node status, method of diagnosis, and pretreatment prostate-specific antigen value has been documented and analysed. Comparison of results with those of radical prostatectomy is discussed.