Aim. Study of the frequency of radiation therapy complications in patients with prostate cancer. Methods. The study included 142 patients who underwent radiation therapy combined with hormonal therapy in 2001-2015. Average age of patients was 68 years. All of them received 3D-conformal radiotherapy by linear accelerators with 6 to 15 MV photon beams. Single boost dose was 2 Gy, total boost dose was 75 Gy. We studied frequency and severity of acute hematological toxicity and early and late gastroenterological and urological complications of the treatment. Treatment-related toxicity was assessed by RTOG/ EORTC and CTCAE v. 4.0 scales. Results. Early radiation-induced proctitis of I, II and III degree were registered in 95 (66.9%), 32 (22.5%) and 8 (5.6%) patients, respectively. Acute cystitis of I, II and III degree were noted in 22 (15.5%), 87 (61.3%) and 16 (11.3%) patients, respectively. Signs of late radiation-induced proctitis of I degree was diagnosed in 21 (14.8%) cases. Late radiation-induced cystitis of I degree was diagnoswed in 37 (26.1%) patients. No late complications of higher severity occurred. Conclusion. The results of the conducted study showed that use of high-tech precision external-beam radiotherapy techniques in the treatment of prostate cancer along with high efficacy allows to reduce the number of early and late complications.