Intravenous human immunoglobulins (IVIG) are valuable in the treatment of several immunodeficiency and autoimmune diseases. The classic, well-known indications are primary hypogammaglobulinaemic conditions, immune thrombocytopenia and Kawasaki's syndrome. IVIG's content of specific antibodies toward a series of known, pathogenic microorganisms has led to the treatment of a number of infectious conditions and IVIG has a documented effect on AIDS in children, prophylactically in cases with potentially life-threatening CMV infections in certain types of transplants and prophylactically in hypogammaglobulinaemic patients with the most common variety of leukaemia, chronic lymphocytic leukaemia. Immunotherapy with IVIG in diseases of autoimmune character such as acute and chronic demyelinating neuropathy has recently shown promising results and encouraging reports have been published in the treatment of severe, steroid-dependent asthma, juvenile chronic arthritis and systemic vasculitis and dermatomyositis where IVIG possibly has a favourable immunomodulating effect on the patient's immune response. Future treatment will probably consist of polyvalent immunoglobulins as well as monoclonal or recombinant monovalent antibodies.