Hepatic resection is the most effective therapy for liver metastasis of colorectal carcinoma. To clarify indications for this therapy, the clinicopathologic and follow-up data of 103 consecutive patients who underwent hepatic resection for metastases of colorectal carcinoma were analyzed. Factors influencing overall survival rate were investigated by multivariate analysis. Thereafter, patients who underwent resection were stratified according to the number of independent risk factors present, and their outcomes were compared with those of 14 nonresection patients with fewer than six liver tumors and without extrahepatic metastasis. The overall survival rate of the 103 resection patients was 43.1%. The clinicopathologic factors shown to affect on long-term survival after hepatic resection were the interval between colorectal and hepatic surgery (<12 months), preoperative carcinoembryonic antigen level (> or =10 ng/ml), and number of hepatic metastases (four or more). The 5-year overall survival rates were 75.0% with no risk factors (n=16), 53.6% with one risk factor (n=46), 23.0% with two risk factors (n=36), and 0% with three risk factors (n=5). Survival rates did not differ between resection patients with three risk factors and nonresection patients. Therefore, hepatic resection may be appropriate for patients with fewer than three risk factors.