Cancer is associated with a fourfold increased risk of venous thromboembolism (VTE). The risk of VTE varies according to the type of malignancy (i. e. pancreatic cancer, brain cancer, lymphoma) and its disease stage and individual factors (i. e. sex, race, age, previous VTE history, immobilization, obesity). Preventing cancer-associated VTE is important because it represents a significant cause of morbidity and mortality. In order to identify cancer patient at particularly high risk, who need thromboprophylaxis, risk prediction models have become available and are under validation. These models include clinical risk factors, but also begin to incorporate biological markers. The major American and European scientific societies have issued their recommendations to guide the management of VTE in patients with cancer. In this review the principal aspects of epidemiology, risk factors and outcome of cancer-associated VTE are summarized.