Aging is the major risk factor for the development of cardiovascular diseases, the leading cause of morbidity, mortality and disability in western countries. Mounting data suggest that cardiovascular structure and function change with time as result of an "aging process", regarded as an independent process which accompanies aging, interwines and modulates superimposed traditional cardiovascular risk factors to determine the peculiar occurrence, presentations and prognosis of heart disease in the elderly. A whole body of data underlies the impairment of endothelial function due to oxidative stress as a crucial feature of the aging process acting on the cardiovascular system. Insights into molecular and cellular mechanisms of age-associated endothelial dysfunction may provide new strategies to treat age-related cardiovascular diseases.