Palivizumab was licensed in June 1998 by the US Food and Drug Administration for prevention of serious lower respiratory tract disease caused by respiratory syncytial virus (RSV) in pediatric patients who are at increased risk of severe disease. Safety and efficacy have been established for infants born at or before 35 weeks' gestation with or without chronic lung disease of prematurity and for infants and children with hemodynamically significant heart disease. The American Academy of Pediatrics (AAP) published a policy statement on the use of palivizumab in November 1998 (American Academy of Pediatrics, Committee on Infectious Diseases and Committee on Fetus and Newborn. Pediatrics. 1998;102[5]:1211-1216) and revised it in December 2003 (American Academy of Pediatrics, Committee on Infectious Diseases and Committee on Fetus and Newborn. Pediatrics. 2003;112[6 pt 1]:1442-1446), and an AAP technical report on palivizumab was published in 2003 (Meissner HC, Long SS; American Academy of Pediatrics, Committee on Infectious Diseases and Committee on Fetus and Newborn. Pediatrics. 2003;112[6 pt 1]:1447-1452). On the basis of the availability of additional data regarding seasonality of RSV disease as well as the limitations in available data on risk factors for identifying children who are at increased risk of serious RSV lower respiratory tract disease, AAP recommendations for immunoprophylaxis have been updated in an effort to ensure optimal balance of benefit and cost from this expensive intervention. This statement updates and replaces the 2003 AAP statement and the 2006 Red Book and is consistent with the 2009 Red Book recommendations.