1. In thoracic outlet-syndrome arterial lesions--such as poststenotic aneurysm with or without peripheral arterial emboli--are mostly caused by permanent compression of the vessel. In 48% of cases arterial emboli show to be the first clinical manifestation of a subclavian artery lesion. 2. Venous lesions usually classified as "spontaneous axillar vein thrombosis" are probably initiated by intimal lesions of the axillary vein caused by compressionof this vessel in the costoclavicular space. 3. Unilateral ischemia of fingers or hand--especially in young patients--should be considered first of all as a peripheral manifestation of a cervical rib-syndrome. Surgical correction should include besides rib resection, lumen control of the poststenotic dilated artery, disobliteration of occluded main arteries and thoracic sympathectomy in cases with several distal arterial embolic occlusions. 4. Venous thrombectomy for acute thrombosis of the axillary and subclavian vein should be combined with the resection of the first rib in order to prevent any further compression to the vein in the costoclavicular space. The use of a temporary a.v.-fistula may be used as an additional mens for keeping the disobliterated vein patent. 5. In the thoracic outlet-syndrome neurological signs and complaints caused by intermittent or permanent mechanical nerve irritation represent the most frequent clinical findings (i.e. 90%). On the other hand in two thirds of patients with arterial or venous complications neurological signs are missed and therefore do no help for diagnosis.