Atherosclerosis (ATS) is a focal and disseminated disease of arterial wall with asymptomatic progression for many years until its first clinical manifestation occurs, such as an acute coronary syndrome or a stroke. Since more than 60% of victims of a first cardiovascular event (CVE) were stratified with a coronary risk of less than 20%, clinicians should consider other tests to identify high risk patients. Among them, B-mode carotid ultrasound was developed to predict the risk of CVE beyond the traditional RF assessment alone. However, epidemiological data on subclinical atherosclerosis are lacking. The purpose of this prospective study was to evaluate the prevalence of subclinical atherosclerosis on femoral and or carotid atherosclerosis across age and gender among adults. The study population included 1620 asymptomatic patients aged from 20-70 y (mean ± SD = 48 ± 12 y), without established CVD, who were consecutively referred from Western Switzerland for therapeutic advice. Cardiovascular risk factors (CV-RF) were systematically screened for each subject, including medical history, physical examination and clinical chemistry. B-mode ultrasound was performed on carotid and femoral arteries by two investigators to detect atherosclerotic plaques (defined as focal thickening of intima-media > = 1.2 mm). The prevalence of ATS reached 61% in men and 48% in women, respectively (p <0.001). Furthermore, there was a significant correlation with the number of the traditional CV-RF (r = 0.31, p <0.001). However, no ATS was detected in 30% of patients with 03 CV-RF. As illustrated in the Table 1, there was an increased prevalence of ATS across age in both genders (p <0.001). However, in contrary to general belief, not all persons aged 050 y had ATS. In conclusion, the results indicate that beyond the epidemiology of the traditional CV-RF, more research should be performed on subclinical ATS in order to improve the primary prevention of CVD.