For many decades, the primary treatment of acute respiratory failure has been mechanical ventilation. Intubation and mechanical ventilation carry complications such as upper respiratory system trauma, barotrauma, volutrauma, oxytrauma, atelectrauma, and nosocomial infection, and they increase mortality. Noninvasive mechanical ventilation (NIMV) applied to a specially selected group of patients has more advantages than invasive ventilation, especially the decreased number of complications. We present a three-year-old girl who had prolonged invasive mechanical ventilation (IMV) and weaning failure due to severe tracheal bleeding after Fontan operation. She could not be extubated for 20 days after admission to our Pediatric Intensive Care Unit (PICU) because of life-threatening airway bleedings from within the endotracheal tube. Owing to the severe bleedings during endotracheal aspirations, it was decided to change her mechanical ventilation to NIMV. NIMV was performed successfully for 12 days without difficulty, and she was discharged from the hospital on the 55th postoperative day with normal clinical findings. Noninvasive ventilation has an increasing use in critically ill children. NIMV should be considered in prolonged mechanical ventilation and weaning failure from IMV in critically ill children.