Three patients with traumatic atlanto-occipital articulation (AOA) dislocation are presented, and an additional 10 well documented cases are reviewed from the literature. Medulla oblongata and/or spinal cord deficits, and evidence of cranial nerve injuries were noted in eight patients. Angiographic evidence of vertebral occlusion or narrowing was demonstrated in four patients. One patient had systemic hypertension, presumably from bilateral traumatic ninth nerve injuries. Five patients ultimately died. A new method of measuring the AOA is introduced.