In the last 40 years, radiotherapy as gained a major role in the curative treatment of rectal carcinoma. Based on a reported incidence of local failure after surgery between 15% and 50%, in patients with T3-4 rectal cancer, postoperative radiation has been proposed in this group of patients. However, postoperative radiotherapy results associated with a relatively high incidence of acute and late toxicity and the reported improvement in local control attained statistical significance only in the MRC randomized trial. A recent publication suggests that postoperative radiation should probably be reserved to the subgroup of pT3 patients with unfavourable features. Postoperative radiation therapy is considered also for patients with G1-2 carcinoma treated with local excision, who do not show lymphatic or venous invasion, and for those with pT2 stage or pT1 carcinoma with involved resection margins.