Background: In this study, it was aimed to evaluate the effect of a physical activity program applied to Alzheimer's disease patients on cognitive functions and depression. Method: This study is a randomised controlled study designed in a pre-test post-test design. It was conducted with 72 patients in total, 36 of whom were interventions and 36 were controls, at the Alzheimer's Day Life Centre. In data collection, a personal information form prepared by the researchers, questioning the socio-demographic characteristics of individuals, Mini Mental Test and Cornell Dementia Depression Scale were used. In the analysis of the data, the homogeneity between the groups in terms of independent variables was evaluated by performing a Chi-square analysis. In the evaluation of cognitive functions and depression levels of the experimental and control groups, t-test was used in the dependent and independent groups. Statistical significance level was accepted as P < 0.05. Results: In the study, the cognitive functions of the experimental group, in which a 12-week physical activity program was applied, were higher than the control group and the difference was significant (P < 0.05). Similarly, the depression scale mean score of the experimental group was found to be better than the depression level of the individuals in the control group, and the difference was significant (P < 0.05). Conclusion: The 12-week physical activity program applied to Alzheimer's disease patients improved cognitive functions and depression levels of individuals.