There is a strong association between cancer and venous thromboembolism (VTE). Cancer patients have a seven-fold higher risk of developing VTE as compared with noncancer patients. In the year following the diagnosis of cancer, 1.6% of patients will develop a VTE event. VTE is one of the main cause of death in cancer patients, accounting for about 15% of deaths. On the other hand, cancer patients represent 15 to 20% of all VTE cases. Beyond classical risk factors for VTE, specific risk factors are associated with VTE in cancer patients: tumor site, stage, histological type, treatment, duration of the disease. VTE occurrence is associated with a poorer outcome in cancer patients: a reduced survival is observed in cancer patients with VTE as compared to non-VTE cancer patients. This impact of VTE on prognosis varies according to cancer characteristics. Conversely, evolution of VTE is different in cancer patients, with a higher short-term risk of mortality and a higher risk of recurrences, including on anticoagulant treatment, also modulated by cancer characteristics.