This prospective study was designed to evaluate morbidity and functional and oncological outcomes in patients with carcinoma of the distal third of the rectum treated by high-dose radiation therapy followed by conservative surgery. Twenty-two patients with adenocarcinoma of the distal third of the rectum treated after June 1990 were included in the study. Mean distances separating the tumor from the upper edge of the levator ani muscle and from the anal verge were 17 mm and 47 mm, respectively. None of the tumors were fixed; preoperative stage, established by endoscopic ultrasound, was T2 in 12 patients and T3 in 10. Patients received induction radiation therapy in two series delivered three weeks apart (40 Gy on the pelvis, then 20 Gy on the tumor only) followed by surgical resection (proctectomy with colo-anal anastomosis in 17 cases and amputation in five). After radiation, two tumors were negative for malignant cells, 12 were Astler-Coller B1, two were B2, and six were C2. Mean safety margin after colo-anal anastomosis was 16.8 mm; all the resection margins were negative. Mortality and morbidity were not increased by the high-dose radiation protocol. Conservation of the sphincter was possible in 80% of patients. All the patients were continent. Functional outcome was rated good in 77% of cases, fair in 9% and poor in 4%. During the mean follow-up of 24 months, there were three disease-related deaths, including one due to a strictly regional recurrence; metastatic dissemination to the lungs occurred in two patients and the remaining 17 patients (80%) were disease-free. These data suggest that high-dose radiation therapy followed by conservative surgery ensures satisfactory functional outcomes in patients with carcinomas of the distal rectum. Evaluation of oncological outcomes will require a longer follow-up.