Between 1978 and 1990 emergency pulmonary embolectomy with the aid of extracorporeal circulation (ECC) was performed for massive pulmonary embolism (PE) in 44 patients (19-73 yrs; 49 +/- 15 yrs). Cardiopulmonary circulation was stable in 16/44 patients but unstable in 28/44; of the latter, 15 had undergone previous cardiopulmonary resuscitation due to cardiac arrest. Diagnosis of PE was obtained clinically in 15/44 patients, by angiography in 13/44, by echocardiography in 10/44, and by perfusion scintigraphy of the lung in 6/44 patients. There were 9/44 (20%) postoperative deaths. Early mortality was significantly higher in previously resuscitated patients (p less than 0.05). There were 2/36 (6%) late deaths. Actuarial survival was 75% after 4 yrs and 71% after 8 yrs. 77% or 35 survivors were in NYHA-class I and 23% in NYHA-class II after a mean follow-up of 4.6 yrs. Pulmonary embolectomy is indicated in patients with central PE and shock; it is advisable in patients with embolism of the main pulmonary artery or its major branches or in patients with contraindication to thrombolysis. Intraoperative insertion of a vena cava filter is recommended for prevention of recurrent embolism. Preoperative resuscitation and duration of ECC are predictors for early death.