In this review we present the current state of knowledge of the mechanisms of their action, their historic introduction into clinical practice.A special emphasis is put on practical experience with immunoglobulin treatment of primary immunodeficiencies. THe article includes recommendations of treatment with intravenous and subcutaneous immunoglobulins, including experience with the transfer from one form to another, description of methods of application and practical comments on immunoglobulin therapy administration currently applied in the Czech Republic