The incidence of deep venous thrombosis and pulmonary embolism increases exponentially with age. This pattern reflects the age-related increase in the frequency of serious medical diseases that require prolonged bed rest and predispose to the activation of hemostatic processes. Treatment with heparin and thrombolytic agents is clearly effective in patients age 65 and older, even though an elevated susceptibility to hemorrhagic complications has been demonstrated. Careful evaluation of individual hemorrhagic risk, a slight decrease of doses, and careful laboratory monitoring may decrease the number of clinically significant bleedings without impairing therapeutic results. Low-molecular weight heparin may represent a major advance in the treatment of thromboembolic disease, but studies that specifically address its use in older patients are needed.