Intravenous immunoglobulin (IVIG) has several effects on the immune system that could have a beneficial influence on disease processes in multiple sclerosis (MS). Owing to its anti-inflammatory properties, IVIG may be beneficial in the treatment of acute relapses and in prevention of new relapses. By promoting remyelination, IVIG could have a beneficial effect on disability and disease progression. Four double-blind trials in relapsing-remitting MS have demonstrated that IVIG reduces the relapse rate and the number of gadolinium enhancing lesions, and in this respect seems comparable to established therapies in relapsing-remitting MS, i.e. interferon-beta and glatiramer acetate. The doses of IVIG that have been used for treatment in relapsing-remitting have varied 10-fold, and the ideal dosage of IVIG for treating MS still needs to be determined. Three studies have been performed to assess the effect of IVIG on chronic visual impairment or established motor symptoms in MS. None of these trials could confirm that established symptoms in MS can be reversed by IVIG. In secondary progressive MS, a large randomized placebo-controlled trial has recently shown that IVIG is without beneficial effects in this phase of the disease. In conclusion, IVIG is a valuable alternative for treatment of relapsing-remitting MS in patients who do not tolerate or are unwilling to take the approved injectable medications, but additional studies are needed to establish the role of IVIG in the management of multiple sclerosis.