Venous thromboembolism is frequent in trauma patients and often runs an asymptomatic course. Prophylaxis in these patients, who often have an increased risk of bleeding, deserves extra attention. After injuries to the lower extremities, low molecular weight heparin is advised during the period of immobilisation. Following hip-fracture surgery, fondaparinux is indicated for 4 weeks. In polytrauma and neurotrauma patients, low molecular weight heparin has shown the best results. Thrombosis prophylaxis also seems to be indicated in burn patients.