PURPOSE: To evaluate the efficacy and clinical results of percutaneous insertion of inferior vena cava(IVC) filter. MATERIALS AND METHODS: Over a two year period, eight IVC filters were placed in eight patients with pulmonary thromboembolism resulting from deep vein thrombosis of the legs. The indications for placement were contraindication to anticoagulation(3), and recurrent pulmonary embolism during anticoagulant therapy(5). Both femoral(7) and jugular(1) routes were used for percutaneous transvenous insertion. To delineate the caval anatomy and to ensure placement just caudal to the renal vein, a cavogram was obtained before filter placement. Bird's Nest (7) and Greenfield (1) filters were inserted. Follow-up information was obtained by means of duplex sonography, CT scan, abdominal radiograph, and perfusion scan of the lungs, followed by clinical evaluation. RESULTS: In all cases, procedures were technically successful. Placement complications occurred in three patients. In one, the filter was inadvertently placed above the iliac bifurcation; in the other two, prolapse of the Bird's Nest filter wire occurred. Occlusion of IVC occurred in two patients, and recurrent pulmonary embolism was suspected in one, who suffered from chest pain and shortness of breath. In the other patients, there was no clinical evidence of recurrence of the pulmonary embolism. CONCLUSION: Insertion of an inferior vena cava filteris a safe and effective method for the prevention of pulmonary embolism when anticoagulant therapy is either ineffective or contraindicated.