In this review we discuss the prevention and treatment of infectious diseases with intravenous immunoglobulins (IVIG). IVIG can be used to prevent infections in primary as well as in certain secondary immunodeficiencies. We also discuss the use of IVIG in the prevention of CMV-disease after organ or bone marrow transplantation. Besides their use in prevention, IVIG can also be used as an additional therapy in sepsis in neonates, in streptococcal toxic shock syndrome and in CMV-disease after bone marrow or solid organ transplantation. We briefly discuss the different preparations of IVIG that are available in Belgium.