The authors report a rare anomaly of the upper cervical spine. After an automobile accident, an 8-year-old child underwent CT of the head. Imaging showed a bony anomaly of the neck that was further imaged with thin cuts through the atlas and axis. This demonstrated an unfused anterior arch of the atlas and fusion of the odontoid process to the anterior arch of the atlas. Neurologically, the child is normal with no decreased range of motion about the cervical spine. After a review of the literature, this seems to be only the sixth reported case. © 2005 Wiley-Liss, Inc.