OBJECTIVE: With the advent of highly active antiretroviral therapy regimens, it is crucial to consider their long-term benefits to risk ratios among HIV-infected persons. The impact of protease inhibitors on the cardiovascular risk is controversial. DESIGN: This observational cohort was designed to investigate the cardiovascular impact of boosted atazanavir (ATV/r), a protease inhibitor that does not provide major dyslipidemia or insulin resistance. SETTING: This study was carried out at the University Hospital of Brest (France). PATIENTS: Among the 229 HIV-infected persons of the cohort, 33 cases treated by ATV/r-containing regimen since less than 6 months were compared to 99 age-matched and sex-matched ATV/r naive controls. INTERVENTION: None. MAIN OUTCOME MEASURE: The main outcome measure was carotid intima-media thickness (cIMT) at the baseline, 6, 12, and 18 months. RESULTS: Although the cIMT was not different at inclusion (0.633 ± 0.05 vs. 0.666 ± 0.09, P = 0.07), the cIMT course significantly decreased (P = 0.018) in cases at 18 months. The differences remained significant even after adjustment on the variables that differed between cases and controls (P