Despite controversy about their effectiveness, low-dose heparin therapy and elastic stockings were the methods most frequently selected by surgeons in a national survey on thromboembolism prophylaxis. These methods were selected even for patients with an extremely high risk of thrombosis. Surgeons responding to this survey apparently did not discriminate between degrees of patient risk, did not recognize the limitations of low-dose heparin and elastic stockings in protecting high-risk patients, and were unfamiliar with more effective methods of prophylaxis, ie, warfarin, dextran, and intermittent pneumatic compression. There is clearly a need for more specific data regarding the safe use of effective thromboembolism prophylaxis in surgical patients.