Patients infected with the human immunodeficiency virus (HIV) may have an antibody deficiency and a deficiency of cellular immunity. Intravenous immunoglobulin (IVIG) preparations may benefit HIV-infected children and adults with recurrent bacterial infections at doses of 200 to 400 mg/kg every 2 to 4 weeks. In addition, IVIG (1 to 2 g/kg) is effective at raising platelet counts to hemostatic levels in HIV-infected patients with idiopathic thrombocytopenic purpura and life-threatening bleeding. Indirect evidence also suggests that IVIG may be effective in preventing Pneumocystis carinii pneumonia. Finally, recent studies suggest that specific anti-HIV antibody preparations may have a therapeutic role, either as immunoglobulin concentrates or as immunoadhesions and immunotoxins. However, further investigations are needed to exclude antibody enhancement of HIV infection by the Fc receptor or the complement receptor.