A 62-year-old woman with Wolff-Parkinson-White syndrome was with recent worsening of dyspnea to New York Heart Association functional status Class III. The patient was diagnosed as having central type chronic thromboembolic pulmonary hypertension. By cardiac catheterization, her mean pulmonary artery pressure was 53 mmHg with total pulmonary resistance 2238 dynes·sec·cm(-5). After medical therapies with tadalafil, furosemide, ambrisentan, beraprost, and warfarin were initiated, percutaneous transluminal pulmonary angioplasty (PTPA) was performed. Following PTPA, life-threating hypoxemia resulting from postoperative reperfusion pulmonary edema developed. High-flow nasal cannula therapy (HFNC) was applied, and 100% oxygen at 50 L/min of flow was required to keep oxygenation. HFNC was continued for 3 days, and the patient was discharged on 8th postoperative day with SpO2 of 97% on 3 L/min of oxygen inhalation. Because of the simplicity of the technique, the lower cost of equipment, and remarkable patient tolerance to the treatment, we speculate that HFNC can take over the post of noninvasive ventilation as first-line therapy for patients with acute respiratory failure.