Adhesion molecule mediated leukocyte migration into the central nervous system is considered to be a critical step in the pathogenesis of multiple sclerosis (MS). We measured plasma levels of the soluble adhesion molecules sPECAM-1, sP-selectin and sE-selectin in 166 MS patients and in 36 healthy blood donors with ELISA. sPECAM-1, sP-selectin and sE-selectin plasma concentrations showed a significant increase in the relapsing-remitting disease course of MS and were elevated during relapse. These findings indicate that sPECAM-1, sP-selectin and sE-selectin might be implemented as paraclinical markers of disease activity in MS with restriction to the clinical course of the disease.