The most savage controversies are those about matters as to which there is no good evidence either way. Respiratory syncytial virus (RSV) is the most important viral pathogen that infects young children. Approximately two thirds of infants are infected with this respiratory virus during the first year of life; approximately one third of those infected develop lower respiratory tract disease, 2.5% are hospitalized, and .1% die.1 RSV infection, more than any other factor, is responsible for the dramatic increase in census in children's hospitals between November and March of each year. Children with complicated congenital heart disease and underlying lung disease or immunodeficiencies and premature infants are at high risk for severe or complicated RSV infection.2 Excess mortality rates also have been noted in those <6 weeks of age when infected.3 During the 40 years since its isolation from humans, we have learned much about the biology of the virus, the host immune response, and the epidemiology, pathophysiology, and clinical manifestations of infection. However, there remains a lack of agreement regarding the optimum management of infants and children with RSV infection.4 For example, marked variations in the use of bronchodilators, systemic corticosteroids, and ribavirin for children hospitalized with RSV infections were observed among nine pediatric tertiary care centers in Canada.4 Lack of consensus regarding management of RSV-induced bronchiolitis cannot be attributed to a paucity of literature. There are at least 14 trials of bronchodilators, 3 randomized trials of systemic steroid therapy, and 11 randomized trials of ribavirin.4 Variation in the clinical management of children with bronchiolitis likely reflects varying interpretation of the published data, personal experiences with the use of different therapies, differing patient populations and demographics, and local practice patterns (“peer pressure”). Not unexpectedly, given its substantial cost, ribavirin continues to be the …