In chronic pulmonary vascular thrombotic disease, pulmonary thromboendarterectomy has proved to be effective in reducing pulmonary hypertension and improving gas exchange. However, persistent pulmonary hypertension and unrelenting reperfusion edema are the main causes of death. We report a case of pulmonary thromboendarterectomy followed by an immediate unfavorable postoperative course with acute and persistent pulmonary hypertension, gas exchange impairment, and heart dysfunction. In this particular case, inhaled nitric oxide was successfully administered.