MS is a demyelinating disease characterized by infiltration of monocytes and lymphocytes into the brain parenchyma, destruction of oligodendrocytes and loss of myelin. Since chemokines play a major role in the migration of monocytes and T cells, we here investigated the expression of the CC chemokines MIP-1alpha, MIP-1beta, and RANTES in brain tissue from MS patients using reverse transcriptase-polymerase chain reaction techniques. Both MIP-1beta as well as RANTES were found to be significantly elevated in brain tissue of MS patients. In addition, MIP-1alpha was also increased, although not significantly. Immunohistochemistry revealed that, whereas RANTES was mainly localized in reactive astrocytes, MIP-1alpha and MIP-1beta immunoreactivity was predominantly found in perivascular and parenchymal macrophages, containing myelin degradation products. Thus, chemokines appear to be associated with MS and an increased chemokine expression may further enhance disease progression by attracting more leucocytes into the brain parenchyma and by activation of effector functions of astrocytes and microglial cells.