OBJECTIVE The purpose of this article is to assess the differences, if any, in the values of carotid artery stiffness parameters between HIV-infected subjects without known cardiovascular disease (CVD) or carotid artery plaques and HIV-uninfected control subjects matched for sex, age, body mass index, and other CVD risk factors (i.e., hypertension, hypercholesterolemia, diabetes, and cigarette smoking). Arterial stiffness is emerging as a predictor of CVD risk. By recording the blood pressure, an automated echo-tracking system implemented in ultrasound equipment allows evaluation of arterial stiffness. SUBJECTS AND METHODS Fifty-four HIV-infected patients without a history of CVD were closely matched for sex, age, body mass index, and CVD risk factors to 54 HIV-uninfected control subjects on an individual basis. Ultrasound studies of carotid artery stiffness parameters were performed using ultrasound equipment with a linear broadband high-frequency transducer. Carotid intima-media thickness was also measured. Repeatability between operators was assessed. Nonparametric Mann-Whitney U test, chi-square statistics, Fisher exact test, Pearson correlation coefficient, and intraclass correlation coefficient were used for statistical analysis. A p value less than 0.05 was considered statistically significant. RESULTS Except for arterial compliance in HIV-infected subjects, arterial stiffness parameters were correlated with age in both groups. Compared with matched control subjects, HIV-infected subjects showed lower arterial compliance parameter values (0.95 [interquartile range, 0.78-1.23] vs 0.76 [interquartile range, 0.62-1.00]; p = 0.0009), whereas other parameters were similar. Repeatability between operators was good. CONCLUSION HIV-infected subjects have an arterial compliance significantly lower than that of control subjects. The impairment of carotid artery distensibility may contribute to subclinical atherosclerosis.