Management of respiratory syncytial virus lower respiratory tract infection in infants is predominantly supportive and symptomatic. Outpatient management requires close attention to feeding, oral hydration, and monitoring of fever, behavior, and respiratory effort. In the small proportion of patients who need hospitalization, clinicians are concerned primarily with oxygenation and the possibility of oxygen desaturation. Appropriate interventions depend on the level of oxygenation as indicated by pulse oximetry or arterial blood gases. Hydration and symptomatic treatment with alpha- or ss(2 )-adrenergic agonist bronchodilators may lessen the work of breathing. The role of these agents remains controversial, however, and anticholinergic bronchodilators are considered ineffective. Current antiviral therapy is limited to aerosolized ribavirin. Immunotherapy with respiratory syncytial virus immune globulin or a monoclonal antibody has not been rewarding in terms of clinical outcome, although the antiviral effect of these agents has been impressive. There is concern about long-term pulmonary sequelae after respiratory syncytial virus lower respiratory tract infection early in life. Several recent studies, including new data reported here, suggest that ribavirin may have a beneficial effect on some of these sequelae, whereas other studies have failed to demonstrate any benefit. Future studies may help resolve this question.