Because deep vein thrombosis (DVT) can occur following orthopaedic procedures, knowledge of hereditary and acquired risk factors for DVT is essential. Hereditary forms of thrombophilia include factor V Leiden and prothrombin G20210A mutations, and deficiencies of antithrombin III, protein C, and protein S. Acquired risk factors include but are not limited to trauma, immobilization, and surgical procedures. In general, athletes have a low risk of venous thrombosis; however, this population is exposed to many acquired thrombogenic risk factors, including hemoconcentration, trauma, immobilization, long-distance travel, and the use of oral contraceptives. Thus, orthopaedic surgeons should consider screening athletes for thrombogenic risk factors, including history of venous thrombosis, hypercoagulable disorders, or high altitude exercise, during preparticipation physicals and preoperative examinations. If a patient is determined to be at high risk of DVT, preventive measures such as physical antithrombotic measures and/or low-molecular-weight heparin should be instituted. If an athlete develops a DVT, a risk factor assessment should be conducted along with anticoagulation treatment in accordance with the American College of Chest Physicians guidelines.