With the development of effective therapies for multiple sclerosis (MS), therapeutic nihilism, which was so prevalent just 10 years ago, has given way to exuberance and optimism. The current mood is understandable because MS is such a devastating disease. Within 10 years of symptom onset, 50% of patients with MS are unable to carry out household and employment responsibilities; within 15 to 20 years, 50% are unable to walk unassisted; and within 25 years, 50% are unable to walk at all. The average annual cost of MS in the United States has been estimated at greater than $6.8 billion, or $34 103 per person. This review summarizes evidence that disease-modifying drugs can significantly improve the course of patients with relapsing-remitting MS (RRMS) and frames key issues relating to the use of current drugs. Major issues confronting experimental MS therapeutics are discussed.