Experimental autoimmune encephalomyelitis (EAE) is a major animal model of human multiple sclerosis (MS). CD4+ T cells are thought to play a pivotal role in the pathogenesis of EAE and MS. In order to investigate the depletion of CD4+ T cells from the systemic circulation as an effective strategy for the treatment of MS, we performed extracorporeal CD4+ T cell adsorption, using a filter to which anti-CD4+ antibody is immobilized as a ligand, in adoptively transferred EAE. Rats treated with CD4+ T cell removal filter (CD4RF) exhibited milder clinical signs of EAE and earlier recovery than those receiving sham treatment. Moreover, the thymic cells from EAE rats treated with CD4RF exhibited a suppressed proliferative response and IFN-gamma production to myelin basic protein. These results suggest that depletion of CD4+ T cells from the systemic circulation by extracorporeal treatment is a potentially useful strategy for treatment of acute phase and relapsing MS.