Thoracic outlet syndrome (TOS) can be a painful, debilitating condition for patients with neck-shoulder-arm symptoms and for physicians because of unawareness of accurate diagnosis. The aim of this study was to confirm more accurate diagnostic criteria, leading some authors to neurogenic TOS. Neurogenic TOS patients were studied with use of previous diagnostic tests (Morley, Wright or Roos test), and the results were compared with normal values. Physical examination of TOS patients revealed sensory deficit of the fourth or fifth finger and they complained of aggravated pain or symptoms when sleeping on their back or upon waking in the morning. On their radiographs, the lowest level of cervical spine demonstrated inferior margin of the T1 vertebral body in the neutral-lateral position. The ratio of patients with cervical kyphotic malalignment was higher. In addition, the lateral end on the clavicle of TOS patients mostly revealed the posterior side of the T1 vertebral body, while normal cases showed the anterior side of vertebra. These findings will significantly contribute to providing appropriate diagnosis for neurogenic TOS.