Deep brain stimulation (DBS) has shown some efficacy in monogenic Parkinson's disease; however, data about its long-term benefit in SNCA mutations remain scarce. Subthalamic nucleus DBS was implanted in a 60-year-old female patient with Parkinson's disease due to SNCA duplication. One year later, the patient walked unassisted and was independent for most activities of daily living, without requiring any anti-Parkinson's medication. To our knowledge, four cases of bilateral subthalamic DBS have been reported previously. This case report adds an additional body of evidence of improved one-year outcome after DBS surgery in a patient with SNCA mutation. This is a case report of a patient with genetic parkinsonism due to SNCA duplication undergoing bilateral subthalamic nucleus (STN) deep brain stimulation (DBS) surgery. The outcome was favorable one year after implantation, with the patient coming off all anti-Parkinson's medications. This further clarifies DBS outcome in monogenic Parkinson's disease.