Background: Respiratory syncytial virus (RSV) is the most important viral cause of lower respiratory tract infection in infants and young children worldwide. No vaccine against RSV is available, but prophylactic interventions have been shown to be safe and effective in clinical trials. Objectives: This retrospective analysis was conducted to examine the health and economic burden of hospitalization for RSV pneumonia. Methods: Nationally weighted hospital discharges for RSV pneumonia among children 4 years old and younger were analyzed by using the Healthcare Cost and Utilization Project National Inpatient Sample. Results: In 1993, there were estimated to be 16,500 hospital discharges with RSV pneumonia, which increased to 19,700 and 20,800 in 1994 and 1995, respectively. Children less than 1 year of age accounted for over 70% of these discharges. Hospital charges (in 1998 dollars) for RSV pneumonia–associated episodes were $295,100,000 in 1993; $392,300,000 in 1994; and $295,800,000 in 1995. Conclusions: With inpatient charges of $300 to $400 million per year in the United States, the disease burden of RSV pneumonia is very high in terms of both morbidity and economic costs. Emerging prophylactic interventions should have an impact on the high burden of RSV pneumonia. (J Pediatr 2000;137:227-32)