Antibody treatment of lower respiratory infection has a long history of success and is receiving renewed interest. A variety of polyclonal and monoclonal preparations are clinically available. Although used primarily for infection prophylaxis, these agents have limited applications in the treatment of established infections. Immune serum was the first effective treatment for pneumococcal pneumonia. Although long-supplanted by the advent of antibiotics, passive immunotherapy for pneumococcal and other infections is being revisited in an era of increasing antibiotic resistance and growing numbers of immunocompromised individuals. Limited clinical evidence supports the use of immune globulins in the treatment of pertussis and severe streptococcal infection. Bone marrow transplant recipients with lower respiratory infections caused by cytomegalovirus or respiratory syncytial virus also may benefit by adjunctive treatment with immune globulins. Additional indications for antibody treatment of respiratory infection may develop with further investigation.