Introduction: The prevalence of psychological problems in elderly Parkinson's patients is high, and interventions are needed to alleviate these problems. This study was conducted to determine the effectiveness of mindfulness-based therapy on anxiety and depression in elderly Parkinson's patients. Methods: The research method was a quasi-experimental, pre-test, post-test design with a control group. The statistical population included all patients with Parkinson's disease with anxiety and depression who referred to psychiatric and psychological centers in Yazd in 2023, of which 30 people (15 in the experimental group and 15 in the control group) were selected by convenience sampling. The data collection tools were Beck Anxiety Inventory (1961) and Beck Depression Inventory (1961). Mindfulness-based therapy intervention was performed in 12 sessions of 20 to 90 minutes, twice a week, on the experimental group, and the control group did not receive any intervention. Data analysis was performed using descriptive tests (mean and standard deviation) and analysis of covariance using SPSS version 24. A P value of less than 0.05 was considered significant. Results: In the anxiety variable, the mean and standard deviation of the experimental group before the test was 93.36±17.77 and after the test was 73.13±11.77, and in the depression variable, the mean and standard deviation of the experimental group before the test was 67.30±13.95 and after the test was 80.20±4.02. (P <0.01). Conclusion: Based on the findings of the study, mindfulness-based therapy can be used to reduce anxiety and depression in elderly patients with Parkinson's disease.