Lower extremity disease (LED), including peripheral arterial disease (PAD) and peripheral insensate neuropathy (PN), is a chronic condition that disproportionately affects older persons and persons with diabetes. LED can result in disabling foot complications (e.g., ulcers, infection, gangrene, or amputation). PAD has been associated with increased risk for cardiovascular morbidity and mortality. For this report, CDC analyzed data collected during 1999-2002 from the National Health and Nutrition Examination Survey (NHANES) to update previously published estimates of the prevalence of LED among persons aged > or =40 years with and without diabetes. The results of this analysis indicated that approximately 18% of persons aged > or =40 years had LED and that LED was twice as prevalent among persons with diabetes as among those without diabetes. Approximately two thirds of persons with LED and half of those with both diabetes and LED were asymptomatic. Multiple complications of LED can be prevented if LED is detected early. Increasing knowledge among clinicians and the public of the prevalence of LED and associated risk factors might lead to early detection, intervention, and treatment to prevent disabling consequences.