We assessed high-density lipoprotein (HDL) anti-inflammatory properties in a cohort of vertically HIV-infected adolescents. We hypothesized that proatherogenic mechanisms related to inflammation and immune activation during HIV infection may impair HDL functionality and impact on the atherosclerotic burden. Compared with healthy controls, HDL from HIV-infected adolescents presented impaired functionality, as determined by its ability to inhibit monocyte chemotaxis in vitro, which correlated with detectable viral loads (P = 0.044), lower CD4 nadir (P = 0.043), increased levels of CD4 T-cell activation (P = 0.018), higher C-reactive protein (P = 0.009), and a tendency toward thicker carotid intima-media thickness (P = 0.071).