Arterial thoracic outlet syndrome (TOS) is the least frequent but likely most complex form of TOS. It most frequently occurs in relatively young, active, and otherwise healthy individuals. It is primarily caused by bony abnormalities, such as cervical ribs and anomalous first ribs. In this condition, longstanding subclavian artery compression leads to poststenotic dilatation and ulceration or aneurysmal degeneration, followed by occlusive thrombosis or mural thrombus formation with distal embolization to the arm and/or hand. Many clinical questions regarding diagnosis and optimal management of arterial TOS remain unanswered. The development of an international registry for patients with arterial TOS, along with standards for characterizing patients and reporting clinical outcomes, would provide useful data to help guide the optimal management of this rare and challenging clinical condition.