During the 15 years from 1972 to 1986, 25 cases of anal cancer were treated in the First Department of Surgery, Osaka City University Medical School. These cancers accounted for 3.8 percent of all colorectal and anal cancers, and 6.3 percent of all rectal and anal cancers treated in our department during that period. Fourteen patients were males and eleven were females. The mean age was 57±3 (M±SE). Most of the patients had anal bleeding and anal pain with a relatively long duration of symptom. Three patients were complicated with anal fistula. Tumors were resected by the abdominoperineal method in 88.0 percent of all patients, and curative resections were performed for 64.0 percent of all patients. Anal cancers showed a variety of histlogical types: 14 adenocarcinomas, 7 mucinous carcinomas, 3 squamous cell carcinomas, and 1 adenosquamous carcinoma. Microscopic lymph node metastasis occurred in 31.8 percent of the patients whose tumors were resected. The cumulative 5-year survival rate was 41.6 percent overall and 49.3 percent for patients whose tumors were resected. It was 64.9 percent for patients curatively operated. Comparing the prognoses of anal cancers and rectal cancers treated in our department, anal cancers had worse prognoses than rectal cancers.