OBJECTIVES: Mild cognitive impairment (MCI) is prevalent among older adults and may progress to dementia. This study evaluated the effectiveness of a game-based brain exercise program in reducing MCI among older adults. METHODS: A quasi-experimental study was conducted with 2 groups of older participants in Pathum Thani Province, Thailand. A total of 96 individuals with Thai mental state examination (TMSE) scores between 12 to 23, indicating MCI but no dementia diagnosis, were recruited. Using multi-stage sampling, participants were divided into an intervention group (n=48) and a control group (n=48). The intervention group participated in a 6-week game-based brain exercise program, while the control group received a self-administered brain exercise manual. Face-to-face interviews assessed outcomes at baseline, post-intervention, and 3-month follow-up. Data were analyzed using descriptive statistics and repeated-measures analysis of variance. RESULTS: Significant differences were observed in mean TMSE scores and MCI knowledge between the intervention and control groups at the 3-month follow-up (p <
0.001). The intervention group showed significant increases in TMSE scores and MCI knowledge postintervention and at 3-month follow-up (p<
0.001). CONCLUSION: The findings suggest that a game-based brain exercise program can improve cognitive function in older adults. Healthcare professionals can implement such programs to reduce MCI by addressing planning, management, and related issues in the future.