Respiratory syncytial virus (RSV) infection is the leading cause of lower respiratory tract infection in infants and young children. Premature infants and infants with underlying lung disease are at increased risk for severe RSV infection in the first 1 - 2 years of life. Monthly prophylaxis with palivizumab (Synagis) during RSV season has been proven safe and effective in this population and these effects have persisted over the 4 years since the drug was approved by the US FDA in 1998. Issues remain regarding the optimal candidates for palivizumab prophylaxis and whether additional groups of high-risk individuals, for example infants with congenital heart disease or cystic fibrosis, and immunocompromised hosts, might benefit from such preventive therapy. It is possible that palivizumab in combination with antiviral or anti-inflammatory agents might also prove to be beneficial in the treatment of RSV disease. Newer monoclonal antibodies to RSV in development may offer the potential for less frequent dosing, increased efficacy and a role in treatment of RSV disease, but pending further evaluation of such products palivizumab provides significant protection for high-risk infants against a major pathogen.