Inflammatory disorders of the nervous and neuromuscular system are not uncommon despite the fact that immune privilege exists in much of the nervous system. Common immune-mediated neurologic diseases include multiple sclerosis, myasthenia gravis, chronic inflammatory demyelinating polyneuropathy, and idiopathic polymyositis. Environmental, genetic, and immunologic factors have been postulated to be involved in the pathogenesis of these diseases, but much remains to be elucidated about the specific identity and relative contributions of these factors. Several new therapies have become available for these diseases in the past few years, and many others are under investigation. Strategies that enhance the normal tolerance mechanisms of the immune system are being developed. In particular, strategies to block T(H)1-type responses or enhance T(H)2/3-type responses have generated interest.