Between 1962 and 1980, 21 patients with anal margin carcinoma were treated with exclusive radiotherapy. They were divided into 4 T1, 7 T2, 8 T3 and 2 T4 cases; only 3 cases presented with an N1 lymph node involvement (1 T2 and 2 T3). The tumor dose was 65 Gy in 22 fractions and 55 days; the inguinal dose was 50 Gy in 15 sessions and 50 days for prophylactic irradiation performed in 9/18 N0 patients, and 65 Gy with a limited 15 Gy boost for the 3 N1 cases. The results are: for T1, 4 patients alive and well out of 4; for T2, 3 out of 7; for T3, 2 out of 8; for T4, 2 out of 2. The overall survival was 11 out of 21 after 5 years. Severe complications occurred in 2 patients out of 21. Sphincter preservation was obtained in 9 patients out of 10 cured cases.