In a case of spontaneous atlanto-axial subluxation occurring at the onset of juvenxile rheumatoid arthritis, the cause was not diagnosed until after fusions had been performed, other joints were affected, and synovial biopsy was done. A review of the literature revealed only one similar case in a child although there frequently is involvement of the cervical spine during the course of chronic rheumatoid arthritis. In the present case, a posterior cervical fusion was performed because of signs of cervical-cord compression. This procedure gave relief.