Viral bronchiolitis is an acute infection and inflammatory disease of the respiratory tract, with infants typically presenting with the most severe symptoms. Medical management of bronchiolitis is mostly supportive. Several preliminary studies suggest potential benefit from the use of high-flow nasal cannula systems. Although high-flow nasal cannula is a well-established modality in the newborn intensive care unit, its use in the pediatric intensive care unit for acute respiratory failure is far less established. The objective of this study was to identify any laboratory and clinical variables that may predict high-flow nasal cannula failure in management of bronchiolitis in the pediatric intensive care unit.