Nerve compression syndromes can be caused by compression of the peripheral nerve from interior or exterior of the nerve. In the upper extremities, brachial plexus, ulnar nerve and median nerve can be compressed in thoracic outlet syndrome, cubital tunnel syndrome and carpal tunnel syndrome respectively. Because these syndromes are caused by compression, decompressive management can be expected to be the principle of treatment. From Jan. 1980 to Dec. 1988, 94 patients were admitted and treated for nerve compression syndromes of the upper extremities in Seoul National University Hospital. Among these, 52 patients suffered from carpal tunnel syndrome and operation was performed to 86 hands. Twelve patients suffered from thoracic outlet syndrome and 25 from cubital tunnel syndrome. Ten patients were treated with conservative method and 84 with decompressive surgery. Satisfactory results were obtained in 92.3% of carpal tunnel syndrome and 84% of cubital tunnel syndrome. Of 4 operated cases of thoracic outlet syndrome, 3 cases were satisfactory.