OBJECTIVE: To compare the clinical characteristics of cervical spine trauma in patients with ankylosing spondylitis (AS) and cervical ossification of the posterior longitudinal ligament (OPLL) with those of a control group. METHODS: A total of 124 patients with cervical spine trauma from January 2004 to December 2013 were reviewed. Fourteen patients were diagnosed with AS and 25 patients were diagnosed with OPLL; 85 patients were controls. C-spine plain radiography, computed tomography, and magnetic resonance imaging were obtained for evaluation of cervical spine trauma. The American Spinal Injury Association impairment scale and Subaxial Cervical Spine Injury Classification were used to evaluate the neurologic status of patients and the fracture mechanism. RESULTS: Patients with AS or OPLL had more spinal injuries associated with minor trauma than did the control group. All patients with AS had spinal fracture injuries after cervical spine trauma, but patients with OPLL mostly had spinal cord injuries without bony fractures. After cervical spine trauma, delayed diagnosis occurred in 3 patients with AS (21.4%) and 4 patients with OPLL (15.6%). Improvement from neurologic deficit after treatment showed better outcomes in patients with AS and OPLL than in controls (P = 0.106). CONCLUSIONS: Patients with AS or OPLL who had cervical spine trauma showed different characteristics and outcomes than control patients. Proper surgical treatment led to better outcomes in both patients with AS and patients with OPLL than in control patients. Moreover, it is important to thoroughly examine patients with AS or OPLL after cervical trauma so as not to delay diagnosis.