The flow cytometric DNA ploidy patterns of colorectal cancers may become available to the surgeon either before surgery, using a superficial biopsy for DNA analysis, or after resection of the cancer. The DNA ploidy pattern may assist in the selection of patients for adjuvant therapy. Recently the measurement of cellular DNA content by flow cytometry is emerging as a prognostic aid in a variety of human tumors. We retrospectively examined 38 patients who were diagnosed as having had synchronous hepatic metastases from colorectal carcinomas between 1982 and 1989. The DNA content of tumor was analysed by flow cytometry on paraffin embedded specimens. The authors measured the correlations between DNA ploidy and age and sex, tumor site, preoperative CEA level, overall survival rate in metastatic colorectal cancers to liver. The result showed that diploid patterns were 12 cases (32%) and nondiploid patterns were 26 cases (68%). In addition, the present study demonstrated that there is more consistent relationship between preoperative CEA level (over 20 mg/ml) and hepatic metastased colorectal cancers for the DNA nondiploid cancers (71%) than for the DNA diploid cancers(13%). However the percent of patients who survived for two years with hepatic metastases were almost identical for patients with diploid and nondiploid tumors, 29% and 21% respectively. And also, the DNA ploidy patterns in hepatic metastases from colorectal cancers have no significant correlations to age and sex, tumor site.