Aim:Apathy is a newly recognized non-motor symptom and has a high impact on the quality of life in Parkinson’s Disease (PD). The effect of subthalamic deep brain stimulation (STN DBS) on apathy is controversial. This study aimed to investigate the impact of STN DBS on apathy and the possible relationship between apathy, depression, and levodopa equivalent dosage (LED) in PD patients. Material and Methods:A total of 26 patients have been evaluated via the Unified Parkinson Disease Rating Scale (UPDRS), Beck Depression Inventory (Beck D), and Beck Anxiety Inventory (Beck A), Montreal Cognitive Assessment (MoCA), Parkinson Disease Questionnaire (PDQ-39) just before and 6 months after DBS.Results:Apathy scores (AES) showed a slight decrease from 54.00±10.30 to 52.69±8.88 without any statistical significance (p= 0.502) after DBS therapy. No correlation was detected between the post-treatment changes in apathy and UPDRS scores, Beck D, Beck A. Although the direction of the correlation between changes in AES scores and LED values was negative, the results did not reach statistical significance. Conclusion:STN DBS therapy does not have a negative effect on apathy in PD Patients. Despite the satisfactory motor improvement, conservative dopaminergic dose reduction after surgery seems to be the main point to prevent apathy increase in PD patients after STN DBS.