Transvenous inferior vena cava (IVC) interruption using the Greenfield filter was performed upon 193 patients from January 1982 to December 1988. Placement of a filter in the IVC was indicated for prophylaxis (23.8 percent), contraindication to anticoagulation (22.8 percent), pulmonary embolism despite anticoagulation (18.7 percent), complications of anticoagulation (26.9 percent) and free-floating thrombus (7.8 percent). Filters were placed in an infrarenal location in 92 percent of the patients. The remaining 8 percent of patients had placement of a suprarenal filter for specific indications, without complication. Most (97.4 percent) of the patients had filters placed through internal jugular or femoral vein cutdown. Five patients required filter placement through a retroperitoneal approach to the right common iliac vein and IVC junction. This new technique of filter insertion is described. The operative morbidity rate was 4.7 percent, with an additional 8.8 percent having postoperative thrombotic complications. The 30 day operative mortality rate (6.7 percent) was related to preexisting associated disease. Nonfatal, late, recurrent pulmonary embolism occurred in 2.6 percent of the patients despite filter placement. Caval patency remains at 97.9 percent in long term follow-up evaluation. The Greenfield filter is an effective and safe adjunct in the treatment of venous thromboembolic disease and a satisfactory prophylactic measure in specific high-risk patients.