Thoracic outlet syndrome is a collective term embracing previously described syndromes such as scalenus anticus, cervical rib, costoclavicular, hyperabduction and shoulder girdle compression syndromes. Its symptoms and signs are due to bony and soft tissue compression of the neurovascular bundle at the thoracic outlet. It is the purpose of this paper to evaluate the results of experience in treating the patient with thoracie outlet syndrome by surgical means. In this study, 3 cases: cervical rib (1 case), excessive callus formation after clavicular fracture (1 case), and hyperabduction syndrome with combined scalenus anticus syndrome (1 case), which had developed thoracic outlet syndrome were treated at Severance Hospital and gratifying results were obtained.