Soluble adhesion molecules E-selectin, intercellular adhesion molecule (sICAM) and vascular cell adhesion molecule (sVCAM) were measured alongside von Willebrand factor (vWf) in 40 patients with peripheral vascular disease (PVD), 43 with ischaemic heart disease (IHD) and in equal numbers of age and sex matched asymptomatic controls. Increased vWf was found in patients with IHD (p = 0.0008) and in patients with PVD (p = 0.0001) relative to their respective controls but levels did not differ between the two patient groups. Raised sICAM was found in both PVD (p = 0.0003) and IHD (p = 0.0059) compared to their respective controls and was higher in PVD than in IHD (p = 0.0088). In the subjects taken as a whole, there was no correlation between vWf and sICAM. Levels of soluble E-selectin and sVCAM did not differ in patients or controls. These data suggest that soluble ICAM may be useful as an index of endothelial cell activation in clinical manifestations of atherosclerosis.