Between 1969 and 1984, twenty-three patients underwent an emergency pulmonary embolectomy under extracorporeal circulation in the Catholic University of Louvain (UCL), Department of Cardiovascular and Thoracic Surgery. The aim of this paper is to delineate the indications of this procedure. Patients were 23 to 70 years old. Diagnosis of Pulmonary Embolism was made according to clinical signs, ECG and Chest X Ray with Swan-Ganz catheter insertion into the pulmonary artery and the help of pulmonary angiogram if time permitted. The surgical technique is briefly described. Four patients died during the immediate postoperative period and three died later. The sixteen survivors all enjoy a normal life.