Cancer increases the risk for venous thromboembolism (VTE) and patients presenting with a seemingly idiopathic VTE often have an occult cancer. Aging also is a risk factor for VTE. Therefore, old patients with cancer are supposed to be at very high risk for VTE, but inherent data are sporadic and contrasting. We reviewed the literature about the relation between cancer and VTE, with particular attention to findings concerning elderly patients. While aging and postmenopausal status enhance the risk of chemotherapy-induced VTE in women with breast cancer, the rate of a cancer diagnosis in the first year after VTE seems to be even lower in elderly compared to young subjects. Thus, further studies are needed to understand whether or not aging and cancer have additive thrombogenic effects. Finally, we discuss prophylactic and therapeutic strategies.