In 109 patients in whom inferior vena caval interruption was indicated to prevent pulmonary embolism, Kimray-Greenfield (K-G) filters were inserted from a percutaneous transfemoral approach, 94 from the right common femoral vein and 15 from the left common femoral vein. All attempts at transfemoral filter insertion were successful except in two patients in whom a left common femoral approach was used. No complications occurred during insertion. In four patients, clinical evidence of femoral vein thrombosis ensued within 48 hours of filter insertion. There were no complications related to filter migration, and in 97% of patients the alignment was satisfactory. The percutaneous transfemoral route is a rapid and effective method for inserting K-G filters. The most frequent postinsertion complication was femoral vein thrombosis (ten patients), but only two patients suffered permanent sequelae.