Therapeutic antibodies include polyclonal immunoglobulins isolated from regular or high-titered human plasma, sera from immunized animals, and monoclonal antibodies. This array of therapeutic antibodies is used for the prevention and treatment of many infectious diseases, antibody immunodeficiencies, autoimmune and inflammatory diseases, neurological disorders, and cancers. Polyclonal human immunoglobulins are available for intramuscular injection (IGIM), intravenous infusion (IGIV) and subcutaneous infusion (SCIG). We review these products and detail the therapeutic use of polyclonal human antibodies in the treatment of antibody immunodeficiencies, including their occasional local side effects (tenderness, sterile abscesses), minor systemic side effects (chills, muscle aches, malaise, headaches) and major side effects (aseptic meningitis, nephropathy, thrombosis).