Mild cognitive impairment (MCI) is a clinical syndrome that presents with memory disorders, normal general cognition, and no compromise of activities of daily living or dementia. Its diagnosis has important clinical implications, since it behaves as a possible predictor of cognitive disorders that would suggest the onset of dementia. Amnestic-type MCI is considered to be a stage prior to Alzheimer-type dementia. The prevalence of MCI varies from 1-29% and the existence of this diagnosis implies a risk of presenting dementia at 12% per year.To establish the prevalence of amnestic-type MCI in a group of persons over the age of 50 years from the Valle de Aburra.The sample was made up of 848 participants of both genders, over 50 years old, who lived in the metropolitan area of Medellin and had different socioeconomic and educational levels. Amnestic MCI was diagnosed according to the criteria proposed by the American Academy of Neurology.Prevalence of amnestic MCI was 9.7%, and was more predominant in males (p = 0.01) than in females. The prevalence was significantly lower in the group with more than 12 years of schooling (p < 0.05), and no significant differences in the prevalence were found in relation to age or economic status.The prevalence of amnestic MCI, 9.7%, found in our study is within the range reported by other researchers.