The spectrum of diseases being treated with intravenous immunoglobulins (IVIg) appears to be ever broadening, including use in neurologic diseases. After a period of anectodal reports and smaller uncontrolled series, recently there have been several randomized, prospective, double-blind, placebo-controlled studies employing IVIg in patients with relapsing remitting (RR) multiple sclerosis (MS). Reduction in relapse rate and some evidence of decreased MRI activity has been reported, but to date no effect on disability or MRI lesion burden has been noted. Because of differences in methodologic design and patient populations, as well as the relatively small number of patients in some of these studies, a rigorous direct comparison of efficacy with the type I interferons and glatiramer acetate is not possible. Given these data and the high cost of IVIg, routine use of this mode of therapy cannot be recommended, certainly not as a first-line treatment. Larger studies would clearly be helpful. At present there is no evidence to support the use of IVIg in secondary progressive (SP) or primary progressive (PP) MS.