Transcranial magnetic stimulation (TMS) is an emerging novel treatment modality for psychiatric disorders, particularly major depression. A device for delivery of TMS was approved by the US Food and Drug Administration for treatment of major depressive disorder in adults. TMS is being studied for a variety of psychiatric disorders, including obsessive-compulsive disorder, post-traumatic stress disorder, and auditory hallucinations in schizophrenia. In this article, we describe TMS and its neurobiologic basis, as well as the efficacy and safety data of TMS with regard to a range of psychiatric disorders.