Background and Importance: A 60-year-old diabetic man with simultaneous diffuse idiopathic hyperostosis, massive ossification of the posterior longitudinal ligament and cervical and higher part of thoracic ligamentum flavum is reported in this article. Such comorbidity rarely occurs. Case Presentation: The patient's chief complaint was sensation abnormalities without gait disturbance or severe cord compression symptoms despite the advanced stage of the disease. Computed tomography scan and magnetic resonance imaging confirmed multi-level involvement of cervicothoracic spine. Conclusion: After surgical treatment, his symptoms resolved completely with no complication.