First rib resection is a controversial solution to a complex problem. The term thoracic outlet syndrome refers to a variety of symptoms usually neurologic but is on occasion vascular and that results from any of a number of anatomic situations. Most patients with thoracic outlet syndrome improve significantly with physical therapy and repetitive behavior avoidance. Only a small number of patients require surgical intervention. When such intervention is indicated, resection of the first rib is the most common approach, but is not the only possible procedure. Some authors recommend subperiosteal resection of the first rib in order to reduce the risk for injury to the neurovascular contents; however, leaving the periosteum intact can lead to reformation of a rudimentary rib, which can cause recurrence of the symptoms. In this chapter, complete resection of the first rib and its periosteum is described. For further discussion of the etiology and treatment of this complex condition, the reader is referred to the references. This uncommon procedure is included because it illustrates regional anatomy well.