Atherosclerotic disease is a major health problem in the elderly population in the U.S. To date, most research has focused on the coronary and cerebral manifestations of the disease. Lower extremity arterial disease (LEAD) has received less attention. However, the use of simple objective non-invasive diagnostic techniques in recent population-based studies has allowed identification of asymptomatic LEAD and shown that the prevalence of disease is several fold higher than previously estimated. The prevalence increases sharply with age, from 3% in those under 60 years to over 20% at 75+ years. Detection of LEAD in the elderly provides a rapid, easy assessment of the level of atherosclerosis in the body and identifies those at high risk for mortality and morbidity. LEAD is associated with a relative risk of 4 to 5 for all cause mortality. In about 25% of those with LEAD, the disease progresses over time, leading to loss of mobility, gangrene or amputation. This review summarizes current knowledge regarding the etiology and natural history of LEAD from an epidemiologic viewpoint, delineating areas in which additional research is needed.