Of the many clinical entities involving the neck region, one of the most intriguing is thoracic outlet syndrome (TOS). TOS is an array of disorders that involves injury to the neurovascular structures in the cervicobrachial region. A classification system based on etiology, symptoms, clinical presentation, and anatomy is supported by most physicians. The first type of TOS is vascular, involving compression of either the subclavian artery or vein. The second type is true neurogenic TOS, which involves injury to the brachial plexus. Finally, the third and most controversial type is referred to as disputed neurogenic TOS. This article aims to provide the reader some understanding of the pathophysiology, workup, and treatment of this fascinating clinical entity.