Multiple sclerosis (MS) represents the prototypic inflammatory autoimmune disorder of the central nervous system and the most common cause of neurological disability in young adults. The mainstays in the immunomodulatory therapy of MS are currently interferon beta and glatiramer acetate, both of which have proven to be clinically and paraclinically effective. Current clinical evidence indicates that treatment should be initiated as early as possible. In this review we summarize available data from clinical studies on clinical efficacy of immunomodulatory drugs for treating patients with multiple sclerosis.