Summary. Cancer patients are at high risk for venous thromboembolism (VTE), which results in substantial morbidity and mortality. In this narrative review, we present evidence for the use of anticoagulants in the treatment and prevention of VTE in cancer patients. The benefit of perioperative anticoagulant prophylaxis following cancer surgery is well established. However, the risk-benefit trade-offs in non-surgical hospitalized cancer patients and among outpatients receiving chemotherapy are more complex. Emerging evidence suggests that the use of low molecular weight heparin (LMWH) may confer a small survival benefit in cancer patients without VTE. However, specific patient populations that may derive the most benefit have yet to be defined. Guidelines endorse LMWH as the preferred treatment for acute VTE, on the basis of high-quality clinical trial data, but the optimal duration of treatment remains unclear, and practical issues may limit its use outside the clinical trial setting. Novel oral anticoagulants may provide additional treatment and prophylaxis options, but their efficacy and safety in this population have not been established. Despite the significant impact of VTE on the lives of cancer patients and the large body of existing literature regarding treatment and prevention, important unanswered clinical questions remain, emphasizing the need for additional high-quality clinical trial data.