Since the NIH Consensus Conference in 1986, the developments in the field of prevention and treatment of venous thromboembolism were mainly characterized by a more specific and extended use of new prophylactic agents such as low-molecular-weight heparins as well as the perception that out-patients may be at risk for thromboembolic complications, too. Therefore, in 1991 and 1995, consensus conferences were held in Europe and North America in order to analyze the risk constellation of various patient populations and to give recommendations for primary prophylaxis and treatment of thromboembolic complications. The most recent, the 1997 International Consensus Recommendations are also discussed.