Background and Aim: Extracranial cerebrovascular atherosclerosis is a common feature of hypercholesterolemia and carotid lesions are good predictors of cardiovascular events in the general population. Factors associated with the carotid damage of hypercholesterolemic patients and their relationships with the occurrence of clinical events are investigated in this study. Methods and Results: One hundred and seventeen cardiovascular event-free hypercholesterolemic subjects underwent a complete clinical examination to look for additional risk factors. A blood sample was collected for lipoprotein determination and an ultrasound high resolution B-mode imaging examination of the common carotid arteries was performed. Patients were treated according to the current guidelines during a 4-yr follow-up and all major cardiovascular events were recorded. The prevalence of subjects with increased intima-media thickness and plaque was 21.4% and 29.9% respectively, higher than in normolipidemic controls. Carotid lesions were significantly related to age, hypertension and LDL-cholesterol and HDL-cholesterol levels. The relative risk of developing a major clinical event was 3.92 (95% CI 1.54-9.95, p<0.004) among categories of carotid status. At multivariate analysis, cardiovascular events were independently related to the diagnosis of familial hypercolesterolemia (FH), baseline carotid score and mean levels of LDL-cholesterol and HDL-cholesterol during the follow-up. Conclusions: Common risk factors cooperate with plasma lipoprotein levels in increasing the frequency of carotid lesions of hypercholesterolemic patients. Since such lesions are useful predictors of clinical events, B-mode ultrasound evaluation of the carotids should be routinely included in the management of these patients.