Rectal cancer requires treatments tailored according to the stage of the disease at diagnosis. In stage I lesions exclusive surgery is the elective treatment. Radiotherapy is used in those cases where the site of the lesion would sacrifice sphincter function. When the features of neoplasm are favourable (size < 5 cm, grading 1-2, histological type adenocarcinoma) local excision and postoperative radiotherapy enable to achieve results comparable to those of radical surgery. In operable lesions (T3-T4 (vagina) N0-2, M0) at high risk for local recurrence, high dose preoperative radiotherapy in some randomized studies has shown a significant improvement in local control and survival with a low toxicity, especially in patients undergoing radical surgery. Concomitant chemotherapy in postoperative radiotherapy has significantly improved local control and survival as compared to radiotherapy alone. Continuous infusion appears to reduce the toxicity, which is otherwise high. Randomized studies of preoperative radiochemotherapy vs radiation alone or vs postoperative radiochemotherapy are in progress in various Centers. Intensification with radiotherapy alone (IORT, fractionation) is also under study. In lesions unresectable for cure (T4, N0-3, M0) radiotherapy alone or combined with surgery did not show significant results. Intensification with concomitant chemotherapy and/or with IORT has enabled over 70% local control and 50% 5-year survival.