In a prospective study of 402 colorectal cancer patients, 133 patients (46 men and 87 women) presented with right colon cancer. There was no significant difference between men and women in right colon cancer incidence. Common presenting features were abdominal pain, weight loss, and anemia. Ninety-one patients underwent resection with curative intent. There were significantly fewer Dukes' A tumors in the right colon cancer series (P less than 0.05). Significantly more women in the right colon cancer group were over 70 years old (P less than 0.05). The findings of peritoneal metastases and poorly differentiated lesions at initial surgery also were associated significantly with women who had right colon cancer (P less than 0.05). This study confirms previous reports of more advanced tumors in the right colon. The need for age, sex, and subsite differences to be taken into account when assessing treatment outcomes or survival is emphasized.