In order to investigate the association between atherosclerosis and risk factors in aged subjects, Doppler ultrasound scans were used to identify the presence and severity of carotid and femoral atherosclerosis in a sample of 457 community living subjects (mean age 55.4 +/- 18.7 years) of the metropolitan area; the ultrasonographic findings were then related to primary cardiovascular risk factors. Carotid and femoral plaques were found respectively in 178 (38.5%) and in 180 (39.4%) subjects. Prevalence of atherosclerosis, number of plaques and percentage of stenosis have been observed to increase with age. All the main cardiovascular risk factors (age, male sex, hypertension, cigarette smoking, diabetes and hypercholesterolemia) resulted significantly associated with both carotid and femoral atherosclerosis in the total series and, more strongly, in subjects aged under 65. On the contrary, most of these associations disappeared in subjects aged 65 or more. Multiple logistic regression analysis confirmed that in this age group only age and male sex were independently associated with carotid and femoral atherosclerosis; of the other risk factors cigarette smoking alone was an independent risk factor for femoral atherosclerosis. We conclude that in the elderly, in spite of the age-related increase in carotid and femoral atherosclerosis, the association between risk factors and atherosclerotic disease is less relevant than at younger ages.