Background : Acute massive pulmonary embolism is a life-threatening disease. It is often treated with thrombolytic therapy, however, the mortality rates are unsatisfactorily high in patients who developed shock and subsequent cardiac arrest. Surgical pulmonary embolectomy is a last resort for patients with hemodynamic instability. We studied the outcomes of our patients who underwent pulmonary embolectomy for acute pulmonary embolism. Methods : Eight patients who underwent pulmonary embolectomy between January 2011 and December 2014 were studied. Our surgical indications were as follows. Patients who experienced cardiac arrest and treated with PCPS, and those in persistent vital shock, with contraindications of thrombolytic therapy, or with right heart floating thrombus. However, patients with ischemic encephalopathy or acute exacerbation of chronic thromboembolic pulmonary hypertension, and those who had already been treated with thrombolytic therapy were excluded. Preoperative ECMO was indicated for those in sustained shock. Pulmonary embolectomy was performed through median sternotomy and with cardiopulmonary bypass. After antegrade cardiac arrest, all clots were removed with forceps under direct vision through incisions in the bilateral main pulmonary arteries. IVC filter (Günther Tulip) was placed through the right atrial appendage. In our early cases, IVC filter (Neuhaus Protect) was placed after chest closure. Anticoagulation was not administered until hemostasis was achieved. Results : Seven patients underwent pulmonary embolectomy for massive pulmonary embolism, and in one patient pulmonary embolectomy was indicated for right heart floating thrombi although the pulmonary embolism was submassive. Three patients underwent cardiopulmonary resuscitation and were treated with ECMO. Other 3 patients in sustained shock vital were electively treated with ECMO. The other patient developed cardiopulmonary arrest shortly after anesthetic induction and intubation, and suffered disturbance of consciousness postoperatively. All patients were successfully weaned from cardiopulmonary bypass and underwent IVC filter placement (5 Neuhaus Protect, and 3 GProtec Tulip). One patient died due to a vascular complication associated with catheter insertion (retroperitoneal hematoma). No patients developed residual pulmonary hypertension. There were postoperative complications including pneumonia in 5 patients, tracheostomy in 2 patients, atrial fibrillation in 3 patients, and pericardial effusion in 1 patient. One patient who suffered disturbance of consciousness died 2.4 months after the surgery. Other patients had not developed any thrombotic and hemorrhagic complications during a median follow-up of 13.1 months. Conclusions : Pulmonary embolectomy is an effective treatment of acute massive pulmonary embolism. We believe that our strategy is useful, consisting of preoperative hemodynamic stability by an institution of ECMO, complete removal of clots by bilateral main pulmonary incisions, and prevention of recurrence by IVC filter placement.