Immunoglobulin is a blood product prepared from the plasma of healthy donors. The therapeutic use of polyvalent immunoglobulins is an established therapy in primary antibody deficiencies, in idiopathic thrombocytopenic purpura (ITP) and in Guillain-Barré syndrome. However, there is an ongoing debate about the efficacy of polyvalent immunoglobulins as adjunctive therapy for sepsis. The paper presented here critically discusses the modern studies investigating the use of immunoglobulins in different diseases. The main focus is the use of immunoglobulins in patients with sepsis or septic shock.