Adjuvant high dose IVIgs are being used increasingly in a range of immune-mediated and auto-immune diseases. Although numerous immunomodulatory mechanisms have been suggested, the exact mechanisms of action are poorly understood. The efficacy of IVIg in certain diseases has been proven in clinical trials, in so far as IVIg is approved as the therapy of choice for Kawasaki syndrome and idiopathic thrombocytopenic purpura. IVIg treatment has been shown to be safe, without many drug-related adverse effects, including systemic immunosuppression, that are related to corticosteriods and other immunosuppressive agents. Current dermatologic uses of IVIg are increasing, which calls for adequately controlled clinical trials. This review evaluates the current published data on the use of IVIg therapy in the treatment of autoimmune diseases and discusses current opinion concerning its potential immunomodulating mechanisms, the industrial preparation and safety features of this biologic agent.