International audienceVenous thromboembolism (VTE) is an independent prognostic factor and the second leading cause of death in cancer patients. VTE is however a largely preventable disease when thromboprophylaxis is appropriately used. As recommended worldwide by international Clinical Practice Guidelines, cancer patients undergoing surgery or hospitalization for acute medical illness or with reduced mobility should benefit from thromboprophylaxis, in the absence of bleeding or other contraindications to anticoagulants. Thromboprophylaxis in cancer outpatients receiving systemic therapies is still under debate, except for pancreatic ambulatory cancer patients where prophylaxis confers a sustained reduction in VTE. Numerous strategies are currently developed to improve VTE prophylaxis practices in cancer patients, and to elucidate the best appropriate anticoagulant regimen for each individual cancer patient