Background/Aims: To investigate associations of the Mediterranean diet (MeDi) components and the MeDi score with mild cognitive impairment (MCI). Methods: Participants (aged 70–89 years) were clinically evaluated to assess MCI and dementia, and completed a 128-item food frequency questionnaire. Results: 163 of 1,233 nondemented persons had MCI. The odds ratio of MCI was reduced for high vegetable intake [0.66 (95% CI = 0.44–0.99), p = 0.05] and for high mono- plus polyunsaturated fatty acid to saturated fatty acid ratio [0.52 (95% CI = 0.33–0.81), p = 0.007], adjusted for confounders. The risk of incident MCI or dementia was reduced in subjects with a high MeDi score [hazard ratio = 0.75 (95% CI = 0.46–1.21), p = 0.24]. Conclusion: Vegetables, unsaturated fats, and a high MeDi score may be beneficial to cognitive function.