Plastic bronchitis is a rare condition in which mucus plugs obstruct the bronchi, potentially leading to fatal respiratory failure. It has been reported in some patients with congenital heart disease following Fontan surgery.We report the general anesthesia management of a 22-year-old female patient with Fontan circulation and type II plastic bronchitis that was controlled using regular intravenous heparin injections. In this case, concerns existed regarding airway obstruction by bronchial plugs and hemodynamic instability specific to the Fontan circulation.During endotracheal intubation, the absence of mucus plugs was confirmed using a flexible bronchoscope.Intraoperatively, ventilation was managed at low pressure to avoid an increase in intrathoracic pressure caused by high positive-pressure ventilation. Additionally, fluid overload was avoided to prevent elevations in the central venous pressure. Consequently, perioperative management can be safely performed without any respiratory or circulatory complications. As treatment outcomes improve, the number of dental and oral surgical procedures in adult patients with congenital heart disease is expected to increase. Therefore, knowledge of congenital heart disease and its sequelae, such as plastic bronchitis, is essential to perform appropriate risk assessment and management.