Intravenous immunoglobulin (IVIG) is sterilized and purified human plasma which contains supra-physiologic levels of immunoglobulin G. IVIG is currently used in the treatment of immunodeficiency syndromes, inflammatory disorders and infectious diseases. Although numerous immunomodulatory mechanisms have been suggested, the exact mechanisms of action are poorly understood. There is also accumulating evidence that high-dose IVIG is efficacious in the treatment of some skin diseases, despite the lack of evidence from randomized, double-blind, placebo-controlled trials. Though in most cases, IVIG is only effective in combination with other immunomodulating strategies, it offers new hope for the treatment of many severe dermatologic conditions. This article focuses on the efficacy and safety of IVIG therapy in skin diseases.