ADAS-COG is the standard for evaluating Alzheimer disease (AD) in clinical trials. Validation of ADAS in Colombia will give the opportunity to compare it worldwide and to conduct multicenter studies. Aim: To adapt and to validate the ADAS-COG subscales in Colombian population, to obtain a Spanish version with trans-linguistic equivalence in patients with Alzheimer disease, mild cognitive impairment (MCI) and healthy subjects. Descriptive-correlational cross-sectional study, for evaluation of diagnostic technology and psychometric validation. Participants: 60 Adult Spanish-speaking Colombian patients, with AD or MCI, either with familial or sporadic types. Methods and procedure: After informed consent, patients were assessed in the Neuroscience Group of Antioquia University or the Interdisciplinary Group on Dementia of the National University of Colombia. Every step of psychometric tests validation studies were followed: Translation - Translation in reverse, validation of appearance, content validity, construct validity, criterion validity (concurrent validity and predictive validity) and reliability (internal consistency and Test - Retest reproducibility). Preliminary results allowed to distinguish subjects with MCI, AD, at different stages. ADAS-COG-Col, has shown positive correlation with CERAD-Col and diagnoses by consensus. Colombian version of ADAS-COG, has been useful to discriminate patients with MCI, AD and healthy subjects. It is easy to use, inexpensive and quantifies the cognitive impairment of AD and MCI subjects. ADAS-Cog-Col will be a valid and reproducible test that will allow the development of clinical research and to compare results between various national and international groups. It will allow clinical trials in Alzheimer's and MCI to be conducted on a multicenter basis.