PURPOSE: Anal cancer is a relatively uncommon malignancy, representig only 1.8 to 3.4% of all colorectal cancers. In the past, an abdominoperineal resection (APR) was the treatment of choice for an anal cancer. Since the introduction of chemoradiation (radiation combined with 5-Fu and mitomycin) therapy which proved to enhance the responsiveness of the lesion, the limited resection with preservation of anal sphincter function became the gold standard treatment of the anal lesion. Few studies have examined the effectiveness of each modality due to the rarity of this disease. We compared the results of treatment in two groups, one treated with APR and the other with chemoradiation, and evaluated the prognosis of the anal cancer and the advantages and disadvantages of each method. METHODS: This study was performed from January 1992 to December 2001 in the Department of Surgery, Chonnam University Hospital. It considered many factors, including sex, age, chief complaint, location of the lesion, size of the lesion, histopathologic pattern, method of treatment, and metastasis, based on a retrospective review of clinical files and biopsy results. RESULTS: For the patients, the male to female ratio was 1.8:1.0; the mean age was 64.6 (47~90); the chief complaint was anal mass; with symptoms of anal bleeding and pain; and the mean prevalence rate of disease was 8.5 months. According to the staging, 4 patients were T1 (14%), 19 (67.8%) were T2 and 4 (14.3%) were T3. By histologic biopsy, there were 23 squamous cell and 5 cloacogenic carcinoma. Four patients were initially treated by an APR at a local clinic, while 22 underwent combined chemoradiation therapy. Of the four patients who underwent a chemoradiation after an APR, two died as a result of liver and bone metastasis. According to the TNM classification, the 5-year survival rates were 75, 67, 60, 83, and 55% for T1, T2, T3, M0, M1, respectively; the 5-year survival was 71% the for combined chemotherapy and radiation and 53% for the APR. CONCLUSIONS: In the anal cancer treatment, remission occured in over 50% of patients treated with combined chemoradiation therapy. Also, when the surgery had added, the prognosis was not worse than primary choice of APR. Therefore, combined chemoradiation therapy should be considered the treatment of choice, reducing the amount of resection and conserving the sphincter function.