Both low and high ankle-brachial index are considered as indicators of systemic atherosclerosis in older HIV-negative adults. Whether those ankle-brachial index values are predictors of atherosclerosis in HIV-positive subjects remains unknown. We measured ankle-brachial index in 139 HIV-infected patients and compared the results obtained with carotid intima-media thickness, a well established marker of subclinic atherosclerosis. Ankle-brachial index was associated with carotid intima-media thickness. Patients with low ankle-brachial index, but not those with high ankle-brachial index, had high carotid intima-media thickness.