Multiple sclerosis is a chronic inflammatory disease of the central nervous system and is associated with periods of disability (relapse) alternating with periods of recovery (remission) and often results in progressive neurologic disability. Scientists believe that multiple sclerosis may be a T cell-mediated autoimmune disease. Treatment with high-dose pulses of intravenous methyl-prednisolone is usually associated with a good outcome in the short term. A recent study suggests that interferon beta-1b may decrease the number of relapses in relapsing-remitting multiple sclerosis by 30 percent and also may decrease the development of new central nervous system lesions. Recently, another clinical trial of interferon beta-1a showed a 31 percent reduction in relapse rate and a significant reduction in the average number of active lesions. A third trial showed that 20 mg of copolymer-1, a random polymer of glutamic acid, lysine, alanine and tyrosine, reduced relapses by 21 percent without significant side effects. Further investigation is needed, but these new treatments show great promise in alleviating this difficult clinical problem.