OBJECTIVE To evaluate the risk of bacterial infection and use of antibiotics in otherwise healthy children infected with respiratory syncytial virus (RSV) admitted to the intensive care unit (ICU). METHODS Demographics, clinical information, interventions and outcomes were extracted from the charts of consecutive patients with laboratory-confirmed RSV infection at Children's Hospital, Boston from October 1990 through April 2002. Patients born at <36 weeks gestational age or with preexisting medical conditions were excluded. RESULTS The median age of the 165 previously healthy infants infected with RSV was 42 days. Almost all patients received supplementary FiO2, and 63 (38.2%) patients required mechanical ventilator support. No patients died. The median length of stay was 3 days in the ICU and 7 days in the hospital. Most patients had bacterial cultures sent: 155 (93.9%), blood cultures; 121 (73.3%), urine cultures; and 85 (51.5%) cerebrospinal fluid cultures. Only 1 blood culture was positive, and 1 potential urinary tract infection was identified in a patient with a negative urinalysis. All intubated patients and 80.4% of nonintubated patients received antibiotic therapy. CONCLUSIONS In otherwise healthy infants admitted to the ICU with RSV infection, bacteremia, urinary tract infection and meningitis are uncommon. Although bacterial pneumonia in this cohort may be more prevalent, overdiagnosis is common.