The serum levels of intercellular adhesion molecule-1 (sICAM-1) and endothelial leukocyte adhesion molecule-1 (sELAM-1) were determined in 40 patients with colorectal cancer. The sICAM-1 and sELAM-1 levels in the drainage venous blood adjacent to a tumor were significantly correlated with those in the peripheral venous blood in patients without evident hematogenous dissemination of tumor cells. The sICAM-1 levels in peripheral venous blood were significantly higher in patients with hepatic metastases, while the sELAM-1 levels were significantly higher in those with pulmonary metastases. An immunohistochemical study of metastatic sites in the liver revealed that ICAM-1 was expressed in cancer stroma, but not in the cancer cells. In conclusion, the sICAM-1 and sELAM-1 levels in the peripheral venous blood in colorectal cancer patients without any distant metastasis are likely to reflect the topical production of these cell adhesion molecules, and appear to be instructive in predicting hematogenous dissemination in patients with colorectal cancer.