A retrospective analysis of 20 patients with anal carcinoma treated at Hospital del Mar (Barcelona) from 1982 to 1995 was performed to evaluate clinical and pathological characteristics. This subset represents 2.1% of all the colon and rectum cancers registered in the same period. The mean age was 74 years (42-92), the female to male ratio was 1.5:1. The most frequent site was anal canal (80%) and the histological type was squamous cell and basaloid carcinomas in all cases. Five aged patients were not treated. Twelve patients were primary treated by abdominal perineal resection, 2 patients by radiotherapy and one by a local excision. The prognosis of 8 patients treated with palliative surgery was poor and none survived 30 months after surgery. In contrast, 4 of 5 patients are alive after radical surgery with a minimum 5 year follow-up. Two patients treated with radiotherapy are disease free at 7 and 13 months after treatment. The incidence of anal carcinoma is low, but our experience shows that it is diagnosed at an advanced stage and surgery is not always successful. Radiotherapy with or without chemotherapy, is an effective alternative.