Radiotherapy has become one of the important ways of treatment of colorectal carcinoma patients. Because the anatomical position of the colon it has been mostly used in rectal carcinoma. Radiotherapeutic approach for rectal carcinoma can be curative, with intention of healing, or with purpose of relieving the patient symptomatology, the socalled palliative irradiation. It can be applicable before, during or after the operative procedure, or it can be combined with chemotherapy. The primary radiotherapy, as the only form of therapy, is applicable in patients with advanced stage of the disease when it is not possible to make the operative procedure, if there are contraindications for the operation or if the surgical intervention has been refused. Because five year survival has been better when radiotherapy is combined with the operative intervention and chemotherapy in Duke’s B and C stage of the disease, the combined form of therapy has become the standard. In the USA the post-operative adjuvant radiochemotherapy has become the standard form of rectal carcinoma therapy. Opposite of this, in part of Europe, especially in some western countries pre-operative radiotherapy and radiochemotherapy have often been used. 

Key words:
colorectal cancer, radiotherapy