Background Deep brain stimulation (DBS) has been used for neuropsychiatric disorders in clinical and research settings for almost 50 years now. Recent evidence demonstrates some efficacy in treating obsessive-compulsive disorder and major depression in patients refractory to other treatment modalities beyond single case reports. This has led to a considerable surge of clinical and commercial interest in DBS for psychiatric indications. Because of the high vulnerability of psychiatric patients, the lack of extensive short- and long-term data about effectiveness and adverse effects and the haunting history of psychosurgery, this new field in psychiatry raises important and specific ethical issues that have only rarely been systematically addressed so far. Objective and Methods We here review an evidence-based systematic ethical analysis of psychiatric DBS using the criteria of beneficence, nonmaleficence, and autonomy. Conclusions These criteria can easily be applied to research and future clinical application of DBS in neuropsychiatric disorders. This will prepare the ground for ethically justified, empirically comprehensive DBS in this highly vulnerable population and allow stringent future societal discussions about its legitimation.