Statins, 3-hydroxy-3 methylglutaryl coenzyme A(HMG-CoA) reductase inhibitors, are approved for cholesterol reduction and are commonly used to treat atherosclerosis and coronary disease. Statins may also be potent immunomodulatory agents and be beneficial in the treatment of autoimmune diseases. Statins have already been used to reduce the rejection of human heart transplants by the immune system, and there have been reports of a protective effect of injected statins in models of brain autoimmunity similar to experimental autoimmune encephalomyelitis. In vitro studies in multiple sclerosis(MS) revealed that statins reduced the expression of activation-induced adhesion molecules on T cells, modified Th1/Th2 cytokine balance, reduced matrix metalloproteinase(MMP)-9, and downregulated chemokine receptors on both B and T cells. Thus statins are effective immunomodulators in vitro that merit evaluation as treatment for MS. In vivo studies using three different animal models of MS revealed that oral atorvastatin prevented or reversed chronic and relapsing paralysis. Atorvastatin has been shown to have pleiotropic immunomodulatory effects involving both antigen presenting cells and T cell compartment. Thus, statins may be beneficial for MS, and clinical trials of the effects of statins on MS are now in progress, hopefully in a favorable way.