Background: Cognitive impairment profoundly influences on older adults’ activities and quality of life. Therefore, optimizing and remediating age-associated cognitive decline have great importance.

Objectives: To evaluate the effect of 8 weeks (3 day /week) computer based brain training on cognitive performance in old women with Mild Cognitive Impairment (MCI).

Materials and Methods: This randomized controlled study was performed in old women with MCI that was measured using the mini-mental state examination (MMSE). Twenty women diagnosed with MCI were divided into two groups of: exercised (trained with computerized brain program for 8 weeks (3 day /week, 30-60 min/day) and control group. Before and after training, reaction time, error number and data processing speed were measured using computer stroop task and digit symbol coding test, respectively. After checking the normal distribution of collected data by Kolmogorov-Smirnov test, the pre and post means difference and differences between groups were analyzed using paired T- test and independent t-test respectively.

Results: Brain training lead to a significant reduction in reaction time (p=0.001), error number (p=0.002) and increase in data processing speed (p=0.011) compared with pre-test values. Also, there were significant differences between experimental and control groups in reaction time (p=0.001), error number (p=0.007) and processing speed (p=0.013).

Conclusion: The findings indicate the efficacy of computer based brain training program on improving the reaction time, error number and processing speed in elderly women diagnosed with MCI and also reflects the plasticity of old brain for challenging to learn new tasks.