The relative infrequency of blunt carotid artery trauma prompted a multicenter review to determine the spectrum of injuries, treatment strategies, and neurologic outcome. During a six-year period, 60 carotid artery injuries from blunt mechanisms in 49 patients were treated at 11 institutions. There were 11 bilateral injuries. Injury mechanisms were diverse but involved motor vehicles in 35 (72%) patients. In 14 (29%) patients, significant neurologic deficits developed more than 12 hours after a normal admission neurologic examination. The diagnosis was confirmed by angiography in 42 (86%). Duplex ultrasound accurately demonstrated the arterial injury in 12 (86%) of 14 patients. Documented injuries included arterial thrombosis in 20 arteries, arterial dissection alone in 19, dissection with pseudoaneurysm in six, pseudoaneurysm alone in five, frank arterial disruption in seven, and carotid-cavernous fistula in three. Arterial dissection was managed nonsurgically in 15 (79%) of 19 cases, the majority with systemic anticoagulation. Arterial thrombosis was managed with supportive therapy alone for 16 (80%) of 20 arteries; most associated with fixed neurologic deficits. Pseudoaneurysm repair was performed for six (55%) injuries. Carotid-cavernous fistulas were treated in all three instances with balloon occlusion. Overall mortality was 16 of 49 patients (43%). Good neurologic outcome was achieved in 22 (45%) patients. We conclude that: (1) Neurologic symptoms may develop in a delayed fashion; prior clinical suspicion and diagnostic testing are essential; (2) arterial dissection without complete occlusion may effectively be managed by anticoagulation; (3) pseudoaneurysms in accessible anatomic locations can be repaired with good results; and (4) injuries with complete arterial thrombosis are associated with high mortality and poor neurologic outcome in proportion to the initial degree of neurologic impairment.