Fingolimod is an agonist at sphringosine-1 phosphate receptors that reduces circulating T lymphocytes. Experimental autoimmune encephalomyelitis is often used as an animal model of multiple sclerosis (MS), and fingolimod prevents or reverses this encephalomyelitis. In subjects with relapsing MS, fingolimod reduced the total number of gadolinium-enhanced lesions detected by MRI, and the total volume of these lesions at 6 months. The annualised relapse rate was 0.77 in the placebo group, and was lowered to 0.35 and 0.36 in the 1.25- and 5.0-mg fingolimod groups, respectively. However, there was no difference in Expanded Disability Status Scale score between untreated MS patients and those treated with fingolimod. After the 6-month core study, all subjects were treated with fingolimod. The annualised relapse rate remained low and the Expanded Disability Status Scale score remained steady for up to 24 months. Fingolimod decreased heart rate and blood pressure. Given the modest clinical benefits reported to date with fingolimod, long-term safety studies need to be undertaken with fingolimod to determine whether the benefit/risk profile justifies the routine use of fingolimod in subjects with relapsing MS.