94 partial interruptions of the inferior vena cava (PIIVC) were carried out in 98 patients between May 1979 and November 1983 with a Mobin-Uddin umbrella filter (58 cases) or a Kim-Ray Greenfield filter (36 cases); one patient who had a double inferior vena cava underwent double PIIVC with a Greenfield filter. The patients (56 women and 42 men) were between 22 and 84 years old (average 60.6 years). Phlebocavography was performed pre-operatively in 93 patients (95 p. 100) and showed thrombus in the IVC (21 cases), common iliac vein (20 cases), ilio-femoral vein (32 cases), femoral vein (15 cases), popliteal and/or sural vein (4 cases); the investigation was considered normal in 1 patient. The diagnosis of pulmonary embolism (PE) was made in 86 patients (87.7 p. 100) on clinical and/or pulmonary scintigraphy and/or angiography data. The main indications for PIIVC were major PE (56 cases) or a threatening venous thrombosis (27 cases); other indications included recurrent PE despite adequate anticoagulation, patients with contra-indications to anti-coagulant therapy and pulmonary hypertension due to thromboembolism; 4 PIIVC were carried out during pulmonary embolectomy on cardiopulmonary bypass. The operative mortality was 3.06 p. 100 (3/98) with a global early mortality of 10.2 p. 100 (10/98); morbidity was 12.2 p. 100 (12/98); there were 5 failures of PIIVC. The long-term outcome was studied in the first 80 cases with a mean follow-up of 18 months (4 to 48 months).(ABSTRACT TRUNCATED AT 250 WORDS)