BACKGROUND: Premature atherosclerosis in HIV-infected patients is associated with chronic infection by itself and adverse effects of antiretroviral treatment (ART). Extra virgin olive oil (EVOO) has a beneficial effect on the cardiovascular system because of its anti-inflammatory properties. The objective of this study was to determine whether the consumption of EVOO improves inflammation and atherosclerosis biomarkers in HIV-infected patients receiving ART. MATERIAL AND METHODS: This randomized, crossover, controlled trial included 39 HIV-positive male participants who consumed 50 mL of EVOO or refined olive oil (ROO) daily. Four participants dropped out of the study. Leukocyte count, erythrocyte sedimentation rate (ESR), high-sensitivity C-reactive protein (hsCRP), interleukin-6, fibrinogen, total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides, malondialdehyde, glutathione-peroxidase, superoxide dismutase, oxidized LDL and von Willebrand factor were determined before the first and after each of the 2 intervention periods. Intervention and washout periods lasted for 20 and 14 days, respectively. RESULTS: In participants with >90% compliance (N=30), hsCRP concentrations were lower after EVOO intervention (geometric mean [GM], 1.70 mg/L; 95% confidence interval [CI], 1.15-2.52) compared to ROO administration (GM, 2.92 mg/L; 95% CI, 1.95-4.37) (p=0.035). In participants using lopinavir/ritonavir, ESR and hsCRP concentrations decreased 62% and 151%, respectively, after EVOO administration. In the whole study population (N=35) we found no difference in analyzed biomarkers after EVOO administration. CONCLUSIONS: Our exploratory study suggests that EVOO consumption could lower hsCRP in patients on ART.