Fracture of the ankylosed cervical spine is a much more serious problem than injury to the normal vertebral collumn. The ankylosed spine may be fractured following relatively mild trauma attributable to loss of flexibility and increased fragility from osteoporosis. The fused spine breaks like a solid long bone, usually completely. Review of the literature shows that the incidence of neurological deficits and the mortality are significantly higher than in comparable patients without ankylosing spondylitis. The fracture often is difficult to reduce and maintain in proper alignment. Neurologic change from spinal cord compression may occur even while the patient is in skeletal traction. Treatment by skull tong traction and anterior fusion is outlined.--Two cases of cervical fracture dislocation causing neurological deficits in patients with ankylosing spondylitis are presented and the relevant literature is cited.