Objective : This study identified the effect of tailored occupational intervention applied to the elderly with mild dementia using the day care center. Methods : This study applied the single-group experimental design to 29 elderly with mild dementia who use the day care center in B area, and conducted a total of 10 sessions once a week, 60 minutes. Intervention consisted largely of group activities and individual activities, and individual activities were conducted one-on-one with various activities necessary to select occupational goals and achieve the goals through consultation between the elderly with mild dementia and the person in charge. The effects of tailored occupational intervention were confirmed through CERAD, BBS, and GDS. Results : Significant differences were shown in the total score of MMSE-KC, time orientation, attention, constructional praxis delayed recall, and trail making test B in the cognitive function changes, and standing to sitting, standing unsupported with eyes closed of BBS in the physical function changes, and in the GDS score in the depression changes (p<.05). Conclusion : Tailored occupational intervention has been shown to be effective in improving cognitive and physical functions of the elderly with mild dementia and reducing depression. This provided a basis for proposing a tailored occupational intervention as an intervention that can be applied to the elderly with mild dementia.