Between 1985 and 1992, 46 patients with epidermoid carcinoma of the anal canal were treated prospectively by a protocol of combined radiation and chemotherapy with 5-Fluorouracil and Mitomycin C. The survival rate, NED-survival rate and local tumour control rate were 84%, 71% and 83% at 5 years. Anorectal function was retained in 33 of 41 patients (80%). We observed severe acute toxicity including three deaths, but very little late morbidity. The only marginally significant prognostic factor (P = 0.06) for local tumour control was T-stage. NED-survival was significantly affected (P = 0.02) by reduction of chemotherapy during the second course.