BACKGROUND: Pulmonary embolus is a potentially lethal complication in patients undergoing surgery for morbid obesity. In a select group of patients at high risk for venous thromboembolic events (VTE), we have chosen to prophylactically insert inferior vena cava filters via a jugular percutaneous approach. We propose guidelines for preoperative insertion of inferior vena cava filters in patients with clinically significant obesity. METHODS: All patients who underwent preoperative insertion of inferior vena cava (IVC) filters as prophylaxis for pulmonary emboli were reviewed. Data regarding body mass index (BMI), prior history of venous thromboembolism, current anticoagulant usage, as well as other patient data were compiled and analyzed. Additionally, all operative notes were reviewed, and operative data were analyzed and compared. RESULTS: 14 patients underwent preoperative IVC filter placement before gastric bypass. Mean patient age was 49.1 +/- 1.52 years and mean BMI was 56.5 +/- 4.45 kg/m2. No complications occurred due to preoperative filter placement, and no pulmonary emboli occurred in this group. Indications for preoperative IVC filter insertion included prior pulmonary embolus (6), prior deep venous thrombosis (7), and lower extremity venous stasis (1). CONCLUSIONS: Vena caval filter placement in the preoperative period can be undertaken safely in bariatric patients. We recommend that routine preoperative vena caval filter placement should be undertaken in all bariatric patients with prior pulmonary embolus, prior deep venous thrombosis, evidence of venous stasis, or known hypercoagulable state. Possible roles for IVC filter placement in this patient population are expanding as more data is acquired.