Patients with cancer are at particularly high risk of venous thromboembolism (VTE). The guidelines therefore strongly recommend thromboprophylaxis but recent surveys clearly show that oncologists are reluctant to use it because of concern over bleeding, absence of validated risk stratification tools and uncertainties concerning the optimal thromboprophylaxis. Hence, it is a real challenge to identify the individual VTE risk of each cancer patient and individually tailor their thromboprophylaxis.