A cross-sectional study was performed to evaluate classical risk factors for cardiovascular diseases and subclinical atherosclerosis by carotid ultrasonography in HIV-positive subjects, naïve or treated with antiretroviral agents. A total of 66 patients were enrolled into the study: 21 subjects were naïve to all antiretroviral agents (group A) and 45 patients were treated with antiretroviral therapy for >or=36 months (group B). The prevalence of carotid plaques was significantly higher in group B than in group A (44.7% versus 0%; P = 0.014). In group B, patients with high 10-year risk of coronary heart disease showed a significantly higher intima-media thickness and prevalence of carotid lesions than those with low risk. Moreover, carotid lesions were structurally comparable to classical atherosclerotique plaques observed in the general population, with iso-hyperechonegic aspects and irregular surfaces. The prevalence of carotid atherosclerosis in experienced patients is higher than in those naïve to highly active antiretroviral therapy and seems mostly associated with a longer duration of HIV infection, more severe lipid metabolism alterations, presence of lipodystrophy syndrome and a more elevated 10-year risk of cardiovascular diseases.