The purpose of this study is to investigate the effects of group exercise program on depression in the elders with dementia. Subjects of this research were selected from the patients of Hyoja hospital(Yongin, Korea). They were elders with dementia having minor to moderate degrees of cognitive function. Twenty-four subjects were randomly assigned into two groups, each with 12 people; exercise group and the control group. The control group only performed general physiotherapy, while the exercise group performed exercise program and general physiotherapy for 8 weeks. Depression of the exercise group and the control group were measured at baseline before the study, at 4 weeks, and at 8 weeks after the study. Depression was measured by Geriatric Depression Scale Short Form Korea Version(GDSSF-K). Firstly, when comparing the levels of depression within the same group, depression was significantly lower in the exercise group, after the group exercise program. However, depression of the control group did not show significant changes before or after the study. Secondly, when comparing the levels of depression of the control group and the exercise group, differences between the levels measured before the study and 8 weeks after the study, was a statistically significant decrease of depression. Thirdly, effects of group exercise program according to the applied period were analyzed showing 8 weeks of group exercise to be more beneficial than 4 weeks. People who performed continuous group exercise program showed decrease in depression compared to the absence of group exercise program. This can infer beneficial effects of group exercise program. Group exercise program had desirable influence on decreasing the level of depression.