We have confined our discussion to two modalities of treatment by means of x-ray therapy which are now being used in order to improve not only the survival rate but the quality of survival in carcinoma of the rectum. Endocavity irradiation should be established as a recognised method of therapy for selected patients with carcinoma of the rectum and it should be universally available. A number of trials are now in progress which we believe will definitely demonstrate preoperative radiation therapy as an established treatment for cancer of the rectum. It is our belief that preoperative external irradiation by means of supervoltage therapy will contribute considerably to improvement in the five-year survival figures. It may be postulated that in view of the fact that external radiation reduces the number of lymph nodes found at surgery it seems reasonable to offer patients receiving endocavity irradiation a simultaneous course of external irradiation. This may further increase the survival rate for patients with localized tumours.