This paper presents 15 cases of deep venous thrombosis of the upper extremity as a complication of previously asymptomatic thoracic outlet syndrome. The diagnosis was based on clinical examination and phlebography. To achieve prompt recanalisation of the vein streptokinase was used. Fibrinolytic treatment was followed by surgical treatment carried out 6 to 8 weeks after resolution of acute symptoms. The surgery consisted of excision of first rib and accessory cervical rib when present through the axillary approach. In 73% of cases complete lysis of the thrombus was achieved which was confirmed by phlebography and resolution of symptoms of venous hypertension.