The purpose of this study was to assess the role of arteriography (AG) in the diagnosis and treatment of vascular trauma in patients with zone 3 penetrating neck injuries. The records of all cases of penetrating neck trauma for the past 14 years at a level 1 trauma center were reviewed retrospectively. Eight hundred forty-four penetrating neck injuries were documented, of which 72 (8.5%) traversed zone 3 of the neck (gunshot, 35; stab, 32; shotgun, 5). Twenty patients (27%) had hard signs of vascular injury (hemorrhage, expanding hematoma, bruit, thrill, neurologic deficit). Twelve of these (60%) underwent immediate exploration, 1 had no significant injury, and 11 had successful surgical repair or ligation of the vascular injury. AG in the other eight patients with hard signs revealed injuries requiring embolization (three patients), urokinase infusion (one patient), and observation (three patients) and one normal examination. Fifty-two patients had no hard signs of vascular injury. Twenty-four of these underwent AG, of which 18 were negative. Positive findings included internal carotid artery narrowings (two patients), external compression of the internal carotid artery (one patient), vertebral artery intimal flap (one patient), and nonbleeding injuries to small, noncritical arteries (two patients), none of which required treatment. Twenty-four of the remaining 28 patients were observed clinically, and 4 patients had negative explorations. Nine patients had ultrasonography performed, but these examinations did not yield any useful information. The absence of hard signs reliably excludes surgically significant vascular injuries in penetrating zone 3 neck trauma, suggesting that AG is not necessary. Hard signs in stable patients should mandate AG because these vascular injuries may be amenable to endovascular therapy.