In our hospital, combination therapy, mainly intra-arterial infusion, is performed for multiple liver metastases of colorectal cancer. The median survival time of the combination group (n = 18), the hepatectomy only group (n = 3) and the best supportive care group (n = 7) were 21.7, 12.5 and 6.1 months, respectively. The prognosis of the combination group was significantly better than that in the other groups (p < 0.0001). Univariate analysis against the combination group revealed that serum CEA was a significant prognostic factor (p = 0.0196). Moreover, we divided the combination group into two groups on the basis of serum CEA either below or above 50 ng/ml. The prognosis of the low CEA group (n = 11), whose median survival time was 25.9 months, was significantly better than the high CEA group (n = 7), whose median survival time was 17.8 months (p = 0.0031). It therefore appears that combination therapy may be of no benefit when serum CEA is above 50 ng/ml.