Patients with cancer are at increased risk for venous thromboembolism (VTE). Prolonged medical hospitalization, extensive surgeries, central venous catheters (CVCs), and prothrombotic chemotherapeutic agents are important risk factors in cancer patients. Recent efforts to improve VTE management in cancer patients are directed toward optimizing prevention during high-risk periods. Prophylaxis with anticoagulants during hospitalizations and the immediate postoperative period is well established, and although extended postoperative prophylaxis for up to 4 weeks is safe, questions remain regarding benefit. Thromboprophylaxis for preventing CVC-related thrombosis is no longer recommended. Research is focusing on using validated risk-assessment models to identify high-risk ambulatory patients who might benefit from thromboprophylaxis during chemotherapy. Although the treatment of cancer-associated VTE is firmly based on the use of low-molecular-weight heparin, questions remain regarding duration of therapy, management of catheter-related thrombosis, use of inferior vena cava filters, and potential therapeutic roles of the newer oral anticoagulants.