Background/Aims: In population studies, different mild cognitive impairment (MCI) definitions have been used to predict dementia at a later stage. This study compared predictive values of different MCI definitions for dementia, and the effect of age on the predictive values was investigated. Methods: This study was conducted as part of an ongoing longitudinal study into the determinants of cognitive aging, the Maastricht Aging Study. Results: MCI best predicted dementia when multiple cognitive domains were considered and subjective complaints were not (sensitivity: 0.66, specificity: 0.78). Age had a strong influence on the sensitivity of MCI for dementia (age 60-70 years: sensitivity = 0.56; age 70-85 years: sensitivity = 0.70). Conclusion: The inclusion of multiple cognitive domains and participants aged 70 years and older leads to the best prediction of dementia, regardless of subjective complaints.