We report a 62-year-old woman patient who slipped and hit the occipital portion of her skull and suffered an acute spinal subdural hematoma caused by head injury. She complained of headache, neck pain, vomiting, dizziness, and was transferred to our hospital. A skull roentgenogram and CT showed occipital bone fracture and thin subarachnoid hemorrhage, and a small amount of acute subdural hematoma on the contra lateral side. Three hours after the accident, she complained of aggravating neck pain. A repeated CT showed acute subdural hematoma at the cranio-vertebral junction extending to the C3 vertrebral body level. At the emergent operation, we found a dural laceration at the foramen magnum just beneath the fracture, and acute spinal subdural hematoma. After evacuation of the hematoma, the patient recovered completely. Spinal acute subdural hematomas after head injuries are relatively rare. In this case, the migration of the extradural hematoma through the dural laceration at the cranio-vertebral junction was supposed to be responsible for the spinal subdural hematoma. It is crucial that a cervical CT be taken to rule out the possibility of spinal hematoma for patients with head injuries complaining of neck pain.