Introduction: Deep brain stimulation of the subthalamic nucleus (STN) is an effective therapy for medically refractory Parkinson's disease leading to significant improvement of Parkinsonian symptoms through functional inhibition of the STN. Aim of this study: To analyze the outcome of bilateral subthalamic nucleus, deep brain stimulation in advanced Parkinson's disease patients. This is a clinical observational study. Material and methods: This is the result of bilateral subthalamic nucleus-deep brain stimulation (STN-DBS) done in 30 patients for advanced Parkinson's disease in the Institute of Neurosciences, Kolkata, during the past 7 years (2013 to 2019, August) by the authors team. Outcome had been analyzed. Results: Excellent outcome was found after the required programming. Ninety percent patients have shown excellent result. The dosage of antiparkinsonian medications was significantly reduced, with a consequent reduction of dyskinesias. Conclusion: The effect of the STN-DBS on the motor fluctuations and on the levodopa-induced dyskinesias led to a significant improvement of motor part of Unified Parkinson Disease Rating Scale (UPDRS [III]) rating.