The indications for immunoglobulin therapy in childhood have been well established for many years: prophylaxis is effective with single small doses, a full substitution needs multiple large applications. All other recommendations are ill-defined and result from wishful thinking rather than from solid clinical data. New is the possibility of safe i. v. Ig-application which could be realized through appropriate modification of gammaglobulin preparations. Some properties of the commercially available products are summarized. Our own experience with one of them is encouraging: as a matter of fact, fully effective gammaglobulin substitution is now possible in patients with antibody deficiency syndrome.