In prospective studies the incidence of deep venous thrombosis, documented by venography, is between 35% and 63% in patients with major trauma. Five independent risk factors for deep vein thrombosis have been identified in these patients: older age, fracture of the femur or tibia, surgery, spinal cord injury and blood transfusion. Mechanical antithrombotic methods and low-dose unfractionated heparin administered subcutaneously moderately decrease the risk of venous thromboembolism but are less effective than a fixed dose of subcutaneous unmonitored low molecular weight heparin. Prophylaxis with oral anticoagulants (International Normalized Ratio 2.0-3.0) is also effective but is much less used because of the bleeding risk. This is particularly the case in patients with intracranial neurosurgery and acute spinal cord injury. Only a few clinical studies have evaluated the treatment of venous thromboembolism in patients with major trauma. If the condition of a patient with major injury allows, the treatment of venous thromboembolism recommended after hip replacement is cautiously applied.