Diffuse idiopathic skeletal hyperostosis (DISH) is characterized by calcifications and ossification of ligaments and tendon insertions. The patients with DISH are susceptible to spinal column injury with trivial trauma due to immobilization of vertebrae and this easily leads to spinal cord injury. However, only few reports on hyperextension injuries of the thoracolumbar spine with DISH exist. Here we report three cases of those who developed delayed leg paraplegia after hyperextension injuries of the thoracolumbar spine with DISH. All cases complained only lower back pain without neurological deficits and plain radiographs showed no fractures at an initial assessment. The spinal fracture caused by hyperextension injury was diagnosed with computed tomography (CT) and magnetic resonance image (MRI) after delayed leg paraplegia occurred. Many of the fractures caused by hyperextension injuries are not detected only with plain radiographs in patients with DISH. Further investigations using CT and/or MRI should be recommended.