Screening vascular ultrasonography was performed postoperatively on 164 consecutive patients being treated with total knee arthroplasty (203 total knee prostheses). This consisted of examination of the femoral and popliteal veins of the operative extremity with color flow and duplex ultrasonography one week postoperatively. All patients received deep venous thrombosis (DVT) prophylaxis with sequential compressive pneumatic stockings, low-dose warfarin, continuous passive motion, and early mobilization. All patients were observed prospectively for thromboembolic sequelae for a minimum of six months postoperatively. The screening study was significantly limited in six (3%) of the 203 total knee prostheses. The overall incidence of sonographically detected proximal DVT or symptomatic calf vein thrombosis was 3% (6/203), and the incidence of symptomatic pulmonary embolism was 2% (4/203). Four of the ten thromboembolic complications occurred after hospital discharge. Results of this study suggest that duplex ultrasonography can be a useful screening method for identification of venous thrombosis after TKA. Patients with asymptomatic proximal DVT can be identified and appropriately treated before development of serious thromboembolic complications. Routine screening for DVT after TKA can avoid the considerable expense, inconvenience, and potential risk of complications associated with prolonged postoperative prophylactic anticoagulation. The combination of sequential compressive stockings, early mobilization, and low-dose warfarin appears to be a safe and effective prophylactic regimen against venous thromboembolic disease in these high-risk patients.