Adhesion molecules are important in cell-cell and cell-basement membrane interactions. They are intimately involved in inflammatory reactions and a role in tumour progression has been postulated. E-selectin, intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1) play a role in cell adhesion to the vascular endothelium, and may have a role in tumour cell dissemination. Soluble forms of these molecules have been described and this study was established to examine these adhesion molecules in patients with breast carcinoma. Serum was obtained from 92 patients with breast carcinoma and 31 age-matched patients with benign breast disease. All samples were obtained prior to surgery. Soluble levels of E-selectin, ICAM-1, and VCAM-1 were significantly elevated in patients with Stage 4 disease compared with controls. (E-selectin 88.6 (47.9) versus 51.4 (18.4) ng/ml; P<0.001: ICAM-1 447 (249) versus 244 (79) ng/ml; P<0.001: VCAM-1 779 (159) versus 552 (135) ng/ml; P<0.001 results expressed on mean (SEM) SD placed above this.). The prognostic value of the adhesion molecules was examined. In patients with Stage 2 disease, elevated VCAM-1 was predictive of decreased survival, even when corrected for T and N status. Adhesion molecules are elevated in patients with advanced disease and elevation in VCAM-1 has prognostic significance in patients with breast carcinoma.