Bronchovenous fistula (BVF) is a rare complication and can cause arterial gas embolism in vital organs, including the heart and the brain, resulting in a high mortality rate. A 51-year-old man developed a BVF during pneumonectomy for lung transplantation, which quickly was diagnosed by transesophageal echocardiography (TEE). He required highairway-pressure ventilation due to his severely restrictive ventilatory impairment and had severe left pleural adhesion due to a history of pleurodesis. Intraoperatively, he had a coronary air embolism and required temporary treatment with central venoarterial extracorporeal membrane oxygenation (VA-ECMO), but showed no postoperative cardiac or neurologic complications. BVF may be formed during lung transplantation because lung transplantation recipients often receive high-airway-pressure ventilation and are vulnerable to bronchi and pulmonary vessel injuries during surgery. Intraoperative TEE can contribute to the early detection of air bubbles in the left heart circulation and is helpful for the prevention of arterial gas embolism.