Mild cognitive impairment (MCI) is a transitional state between normal aging and dementia. Identifying this condition would allow early interventions that may reduce the rate of progression to Alzheimer's disease (AD). Objective: To evaluate the efficacy of six months cognitive training program (CTP) in patients with MCI. Forty six MCI subjects assessed with neuropsychological, neurological, neuropsychiatry and functional assessment were included in this study and followed up during a year. The sample was randomized in two subgroups: twenty four participants (the “trained group”) underwent CTP while twenty two (control group) received no treatment. Sixteen were dropped out. The intervention focused on teaching cognitive strategies two hours twice a week. Global Cognitive (Mini Mental State Exam (MMSE)) and Functional (Clinical Dementia Rating (CDR)) measures were used as primary outcome measures. The intervention effect (mean change from baseline to final assessment) was significant (p < .05) on MMSE (1.74), CDR (0.14), BNT (2,92), block design (-13,66), matrix reasoning (-3,07), and semantic fluency (-3,071). Four patients (1 trained and 3 non trained) progressed to dementia. These results suggest that persons with MCI can improve their performance on cognitive and functional measures when provided with early cognitive training and it could persist in a long term follow-up.