OBJECTIVE To review the pathophysiology, symptoms, and treatment of multiple sclerosis (MS). METHODS Recently published clinical literature identified through review of articles abstracted at MEDLINE. Search terms included multiple sclerosis, interferon beta, glatiramer acetate, mitoxantrone, treatment, symptoms, steroids, etiology, and neutralizing antibodies. METHODS Performed manually by the authors. METHODS Performed manually by the authors. RESULTS MS is a chronic disease of the central nervous system that most often strikes patients in their early 30s. Noticeable geographic, ethnic, racial, and sex differences in incidence remain unexplained. Diagnosis relies heavily on the presence of neurologic signs and symptoms, and magnetic resonance imaging of the brain is increasingly useful. Treatment with steroids, interferon beta-1b (Betaseron-Berlex) and interferon beta-1a (Avonex-Biogen; Rebif-Serono), and glatiramer acetate (Copaxone-Teva) can produce periods of remission in patients with MS. Management of adverse medication effects and disease-related symptoms of fatigue, pain, and bladder dysfunction is important in these patients. CONCLUSIONS MS is currently incurable but largely treatable. Research has produced promising new medications, and investigational therapies hold promise for better treatment of this debilitating condition.