Aims: The present study set out to evaluate the psychometric properties of the Cognitive Telephone Screening Instrument (COGTEL) in 2 different samples of older adults. Methods: We assessed COGTEL in 116 older adults, with retest after 7 days to evaluate the test-retest reliability. Moreover, we assessed COGTEL in 868 older adults to evaluate convergent validity to the Mini-Mental State Examination (MMSE). Results: Test-retest reliability of the COGTEL total score was good at 0.85 (p < 0.001). Latent variable analyses revealed that COGTEL and MMSE correlated by 0.93 (p < 0.001), indicating convergent validity of the COGTEL. Conclusion: The present analyses suggest COGTEL as a brief, reliable, and valid instrument for capturing interindividual differences in cognitive functioning in epidemiological and aging studies, with the advantage of covering more cognitive domains than traditional screening tools such as the MMSE, as well as differentiating between individual performance levels, in healthy older adults.