Maintaining cognitive function is essential for older adults with dementia. The purpose of this study was to investigate the effectiveness of Smart Restored by Learning Exercise (SRLE) on cognitive functions, neuropsychiatric symptoms, and frontal lobe functions in elderly people with dementia. A total of 68 older adults with dementia participated in this study. A quasi-experimental design was used, and convenience sampling and assignment approaches were adopted to select the participants for experimental and control groups. The experimental group engaged in SRLE for 6 months. The control group received routine care without SRLE. The participants' cognitive function, neuropsychiatric symptoms, and frontal lobe function at baseline were evaluated using the Mini-Mental State Examination (MMSE), Neuropsychiatry Inventory (NPI), and Frontal Assessment Battery (FAB), respectively, in month 3 and month 6. The Group by Time interaction was statistically significant for MMSE and FAB scores, which indicated the different group effects between months 3 and 6. The results also showed that the improvement of MMSE, NPI, and FAB scores in the SRLE group were significantly better than the control group (t = -5.99~4.90, p < 0.001) at both months 3 and 6. In conclusion, long-term facilities may provide residents with SRLE every day to prevent a decline in the residents' levels of cognitive function.