This is a study of 41 patients with squamous carcinoma of the anus. There were 23 with a carcinoma situated above the dentate line, the five-year survival rate being 27%, and 18 with a carcinoma below the dentate line, with a five-year survival rate of 30%. Advanced local and lymphatic spread at the initial examination was a prominent feature of the series. CONCLUSIONS The records of 41 patients with squamous cell carcinoma of the anal canal and anal margin are reviewed. An exact follow-up study was possible in every instance. There were 23 individuals with carcinoma of the anal canal and 18 with carcinoma of the anal margin. Spread to local structures or lymph nodes was observed in nearly half of the patients with anal canal carcinoma, and less frequently in anal margin carcinoma. The preferred method of treatment for anal canal carcinoma was a Miles abdominoperineal resection, and for anal margin carcinoma wide local excision. The combined five-year survival was 28.6%, being 27% for anal canal carcinoma, and 30.5% for anal margin carcinoma.