Pulmonary embolism (PE) is one of the increasing diseases in Japan, which is aggravated rapidly and early diagnosis is necessary to improve its prognosis. We experienced three cases of successful surgical salvage. It is emphasized that the Doppler ultrasonic echocardiography plays important part in diagnosing PE early and noninvasively. Namely, it shows a appearance of acute cor pulmonale, and is usually able to guess the pulmonary artery pressure by using the simplified formula of Bernoulli's equation. We believe that the surgical pulmonary embolectomy under the cardiopulmonary bypass should be immediately considered in case of unsatisfactory conservative thrombolytic therapy.