Prophylactic treatment against deep vein thrombosis has become a routine part of surgical treatment. The indications and the form of prophylaxis selected depend on the patient's individual risk profile, which is determined in turn by a combination of exposing and predisposing risk factors. The exposing risk factors depend on the type of surgery and trauma the patient is exposed to, while the predisposing risks are determined by factors peculiar to the patient. This review deals with the modalities of prophylaxis current-ly available, pharmacological details relating to these, and their clinical significance. In addition, evidence-based data, recommendations for the duration of prophylaxis derived from official guidelines, and medicolegal aspects are discussed. The development of new anticoagulants is expanding the range of prophylactic methods, which means further in-formation is needed.