Objectives: To study the reliability/stability of the Cognitive Telephone Screening Instrument (COGTEL) for the assessment of cognitive functions, and to investigate the concurrent validity (that is, the relationship between the COGTEL scores and external variables, such as level of education and MMSE results) in a pilot study of elderly persons residing in the community in the municipal regions of Apuí, Fonte Boa and Manaus (Amazonas, Brazil). Method: This pilot study included 90 elderly persons (29 men and 61 women) aged 60-85 years of age [68.2 (± 6.7)]. The COGTEL, the MMSE and socio-economic survey were applied in the form of two interviews, a week apart and under the same conditions. Results: The test-retest intraclass correlation coefficient of the COGTEL total score (and respective six subtests), MMSE and educational level ranged from acceptable to high (0.708 < R <0.946). There was a strong positive correlation between the total score of the COGTEL with the MMSE (r =0.682; p <0.001), as well as with educational level (r =0.604; p <0.001). Conclusion: This study presents preliminary evidence of the reliability/stability and concurrent validity of the COGTEL in the evaluation of cognitive functions in elderly persons residing in the community. The results of this study support the use of COGTEL as a short, reliable and valid instrument for analyzing differences in cognitive functioning in inter-individual studies with elderly persons.