Background.The recent number and rate of infant hospitalizations with a respiratory syncytial virus (RSV)-coded diagnosis have not been published.Methods.Retrospective data analysis. National Hospital Discharge Survey data for 1997 to 1999 were analyzed for discharges of infants <1 year old with an RSV-coded diagnosis (ICD-9-CM 466.11, 480.1, 079.6). Hospitalization rates were estimated with annual midyear Census data.Results.RSV bronchiolitis was the leading primary diagnosis annually for all infants hospitalized for any reason. Between 1997 and 1999, 297 684 RSV-coded discharges of infants with an RSV-coded diagnosis occurred. The associated hospitalization rate was 25.2 per 1000 infants. RSV-coded discharges peaked in February.Conclusion.RSV bronchiolitis was the leading cause of hospital admissions of infants younger than age 1 year for any reason between 1997 and 1999.