Four patients with traumatic occipitoatlantal dislocation are presented. The dislocations were the result of rapid deceleration motor vehicle accidents. The mechanism of injury was by hyperextension-rotation combined with a distraction force. Three patients sustained multiple inju- ries. Neurologic findings were variable. One patient with complete cord transection and closed head trauma died 4 days after the injury. In the three surviving patients, the occipitoatlantal dislocation was not diagnosed by the initial examiner. Prompt recognition and stabilization are essential to avoid further neurologic injury. Care must be taken not to increase the dislocation. A halo applied before operation facilitates reduction and allows posterior occipitoatlantal fusion to be performed under optimum conditions.