Twenty-four patients with carcinoma of the anus were treated with a combined regimen of external irradiation (50 Gy) and mitomycin C and 5-fluorouracil. A relatively large number of patients with locally advanced disease were included. A local complete response rate of 87.5% was obtained. The major acute toxicity was dermatitis/mucositis, necessitating a split course in 14 cases. After treatment four patients had persistent anal incontinence. After an observation period of 40-70 months 14 of the patients were alive without disease. We conclude that the conservative combined radiotherapy/chemotherapy regimen is an effective treatment also of advanced anal carcinoma, with tolerable toxicity and with promising survival results.