Patients with cancer are at high risk to develop venous thromboembolism, and they are also more likely to develop complications from anticoagulant treatment. Because little research has focused on the oncology population to date, the optimal methods of prophylaxis and treatment remain uncertain in some clinical situations. Currently, low molecular weight heparin and warfarin are the most frequently used pharmacologic agents; however, they have their limitations. Other therapeutic options, such as inferior caval filters, are poorly studied and remain controversial. A summary of the most recent evidence on the prevention and treatment of venous thromboembolism in cancer patients is presented here.