Plastic bronchitis is a condition in which large, bronchial casts with rubber-like consistency develop in the tracheobronchial tree and cause airway obstruction. We describe a 4-year-old girl who had Fontan physiology and who developed plastic bronchitis and report for the first time the use of aerosolized tissue plasminogen activator for treatment of this condition. The literature is reviewed with emphasis placed on the occurrence of this disorder in patients with single ventricle physiology.