Venous thoracic outlet syndrome is caused by subclavian vein obstruction with or without thrombosis. The primary symptom is arm swelling, frequently accompanied by cyanosis, pain, and occasionally paresthesias. Venography is the only reliable diagnostic tool. Therapy has three goals: (1) remove the thrombus (in thrombotic cases), (2) remove the extrinsic compression, and in a minority of cases, (3) remove the intrinsic stenosis.