BACKGROUND: Intima-media thickness (IMT) is a valid marker for generalized vascular disease whose main risk factors are associated with food habits and lifestyle. A Mediterranean food pattern may have a protective effect on cardiovascular mortality. OBJECTIVE: To assess the relationship between carotid IMT and olive oil consumption. METHODS: One hundred and ninety nine patients were randomly extracted from 1055 asymptomatic high cardiovascular risk participants at the AP-UNAV recruitment center of the PREDIMED (PREvención con DIeta MEDiterránea) project. Demographic and clinical variables were collected, and a validated semiquantitative food frequency questionnaire (137 items) was administered at the inclusion interview. A B-mode ultrasound imaging technique was used to measure the mean common carotid IMT. RESULTS: The mean age was 67.3 years and 53.3% were women. Energy-adjusted olive oil consumption quintiles were assessed as the main exposure after adjusting for potential dietary and non-dietary confounders. Using continuous carotid IMT as the outcome in an ANCOVA analysis, the adjusted IMT means throughout quintiles showed an inverse association with a plateau after the second quintile, with statistical differences when the adjusted IMT mean of the merged four upper quintiles were compared with the lowest quintile (p<0.05). The averaged (both sides) mean IMT of the common carotid was dichotomised and values above the median (0.804 mm) were used to identify carotid atherosclerotic damage. We also found an inverse association of olive oil consumption with high IMT, throughout the second to the fifth quintile as compared with the lowest quintile. The adjusted OR was of 0.08 (95% confidence interval, CI, of 0.02-0.37; p=0.001) after merging the four upper quintiles. CONCLUSION: The inverse association between the olive oil consumption and the carotid IMT could suggest a protective role of olive oil against the development of carotid atherosclerosis in persons at high cardiovascular risk.