Objectives and methods: A descriptive cross-sectional study in 90 children aged from 2 months to 2 years old with acute bronchiolitis admitted to the Pediatric Departement, Hue Central Hospital from April 2010 to March 2011 was conducted to describe the epidemiological, clinical, and laboratory features of RSV and non-RSV acute bronchiolitis, and to evaluate the correlation between RDAI (Respiratory Distress Assessment Instrument) and the clinical and laboratory features.