Abstract Introduction: The prevalence of depression in Parkinson's patients is significantly higher than in the general population or patients with general medical status other than Parkinson's. Considering the importance of depression and its preventive and therapeutic potential in patients with Parkinson's disease and the possibility of improving the quality of life in these patients as well as the lack of such a study in Ahvaz, this study aimed to investigate the prevalence and effective factors in depression in patients with Parkinson's disease. Material and Method: This study was cross-sectional and descriptive-analytic that was performed on 36 patients referred to the Parkinson's disease association of Ahvaz Golestan Hospital in 2017(march to September). The patients are analyzed by demographic questionnaire and Beck depression test. Finally, all analyses were performed using SPSS software version 22. Results: Of the 36 patients with Parkinson's disease, 4 (11.1%) had no depression, 9 (25%) had borderline symptoms, 8 (22.2%) had mild depression, 10 (27.8%) had moderate depression and 5 Patients (13.9%) had severe depression. In general, mean depression was 20.25±9. depression was higher in married people and urban population and old higher61.(p < 0/05) Conclusion: Overall mean depression in Parkinson's patients was 20.25±9 which was in the range of moderate depression and was not correlated with job, body mass, education level, income, duration of illness and occupation but marital, age And the location was related Keywords: Depression, Parkinson'sdisease,.