Objective : This study aims to identify the effect of an occupational therapeutic intervention program including horticultural therapy on cognition and daily living performance of the elderly with dementia. Methods : For the purpose, the study measured the changes before and after the therapy, targeting sixteen women with dementia who were living in nursery facilities. We used MMSE-K to analyse the cognition, and evaluated daily living performance using K-MBI(p<.05). Results : The results of the study were presented as follows: 1. To identify changes of MMSE-K before and after the therapy between the control and test groups. As a result, it was discovered that MMSE-K of the control group was 16.25±1.38 before the therapy and 16.00±.92 after the therapy, which indicated no significant differences, but MMSE-K of the test group was 16.00±1.51 before the therapy and 17.87±1.35 after the therapy, which was statistically significant (p<.05). 2. To identify changes in daily living performance(K-MBI) between the two groups before and after the therapy, and it was discovered that scores of the control group were 74.00±1.30 before the therapy and 74.25±1.16after the therapy, which showed no significant difference, but those of the test group were 73.75±1.28 before the therapy and 76.37±1.30 after the therapy, which was statistically significant(p<.05). Conclusion : Based on the results above, it was demonstrated that the an occupational therapeutic intervention program including horticultural therapy had a positive effect on cognition and daily living performance of elderly women with dementia and it is suggested that the results can be used as basic data for clinical intervention of the elderly with dementia.