Thirty-five patients with low-lying rectal adenocarcinoma have been treated with intracavitary radiation (Papillon's technique). Twenty-three were treated for cure and 12 for palliation. The indications for curative intracavitary radiation were mobile polypoid tumors, less than 3 cm in diameter, with Broder's Grades I and 2 differentiation lying less than 11 cm from the anal verge. Doses between 2 000 and 4 000 cGy were delivered to a total of 7 000 to 20 000 cGy with complete resolution of the tumors. Eighty-seven per cent in the curative group are alive and well up to 42 months after treatment with a minimum follow-up of six months. Of the 23 patients treated for cure, three patients had recurrences within 18 months of therapy. Two of the three patients are alive following surgery. The third patient died in the postoperative period. The results of intracavitary radiation are comparable to ablative surgery and avoid a permanent colostomy. Age, frailty, or other medical conditions do not preclude this treatment. Anesthesia and hospitalization are not required. This method can also be used for palliation of recurrent tumors and in patients who are unsuitable for surgery.