A questionnaire concerning the prophylaxis of venous thromboembolism was filled in by 326 surgical departments in Italy. In 58% the prophylaxis was routinely used and in 29% more than one method was used. The most used method of prevention was subcutaneous heparin followed by elastic compression. In 51% of the centers the prophylaxis was used only in high risk patients and in 22% it was not used at all. The most relevant risk factors in the development of thrombosis were considered age, tumors and obesity. Finally in a questionnaire sent to 350 vascular laboratories it was found that--according to the operators--76% of all documented thromboses were possibly consequent to surgical procedures (in 86% no prophylaxis had been used).