The authors propose a therapeutic strategy enabling diagnosis, treatment and prevention in the same clinical procedure based on a series of 8 patients presenting with signs of massive pulmonary embolism (acute cardiorespiratory distress, shock, loss of consciousness, and/or cardiac arrest). A removable vena cava filter is rapidly introduced percutaneously via a brachial, femoral or jugular vein, and opened in the inferior vena cava. Using the same catheter and without a second venous puncture, pulmonary angiography and cavography are performed by digitised angiography using a small quantity of contrast medium (40 ml, 12 ml/sec). The diagnosis of massive pulmonary embolism (index of pulmonary obstruction 70 to 90%) was confirmed in 6 out of the 8 cases. In 2 patients, the contrast medium passed from the right atrium into the left atrium and one of the patients developed hemiplegia. Thrombolytic drugs (rt-PA followed by Streptokinase) were injected via the same filter catheter. The dosage of rt-PA was 20 to 50 mg as a bolus followed by 50 mg in 2 hours. Streptokinase was then infused at a dose of 100,000 U/hour for an average of 36 hours (24-48 hours), followed by intravenous heparin and oral vitamin K antagonists. Two patients required blood transfusion for haemorrhage during the relay with heparin. The temporary caval filter was removed in all cases but 3 patients required a definitive filter because of the persistence of life-threatening venous thrombosis. Seven of the 8 patients survived their pulmonary embolism. This approach is rapid, saves time, and spares the patients from more invasive procedures.