It is clearly demonstrated that symptomatic and fatal venous thromboembolic complications in patients at risk of venous thromboembolism (VTE) are reduced with the use of thromboprophylaxis. It is one of the most important practices for improving safety of these patients mainly in hospitals, but also after their discharge. Multiple, proven thromboprophylaxis options are currently available. A complex approach is important, using pharmacologic as well as mechanical modalities. At present, low dosed unfractionated heparin and low molecular weight heparins play the most important role in the prevention of VTE. New antithrombotic agents such as pentasaccharides and the oral direct factor Xa and thrombin inhibitors are introduced to the clinical practice. To be effective, pharmacologic prophylaxis of venous thromboembolism must be appropriately prescribed with respect to the type, dose and duration. The objective is to receive appropriate thromboprophylaxis based on the actual thromboembolic and bleeding risk of each patient.