This research aims to estimate the psychometric properties of the neuropsychological assessment instrument - Neuropsi in patients treated in the Neurology area of a public hospital in Peru. The study is of a technological, psychometric type, of a non-experimental and cross-sectional design and is oriented through a quantitative approach. We worked with a non-probabilistic sample of 432 medical records of elderly patients who were diagnosed with or without cognitive disorders or dementia, to whom the brief neuropsychological assessment instrument in Spanish - Neuropsi was applied. A factor analysis was found that reports a good fit in a 6-factor model with X2 = 2.825, CFI = 0.990, GFI = 0.986, PNFI = 0.460, AIC = 47.774, SRMR = 0.0196, RMSEA = 0.065 and the Cognitive performance differs according to the age range of the patient. In addition, it has a Cronbach's alpha reliability of .863. These findings suggest that the instrument is valid, short, accurate, and adequate for measuring cognitive performance.