This is a report of a rheumatoid arthritis patient after atlantoaxial stabilization and halo external fixator immobilization who presented with intracranial injury after an accidental fall. Global aphasia and an impaired consciousness resulted from a cerebral hemorrhagic contusion below an impressed bone chip at the left posterior halo-pin site. Cranial penetration of a halo pin has been previously reported; however, brain injury associated with it has not. Since there is a considerable risk of falls in the elderly and in patients with myelopathic gait disturbances, this rare but potentially hazardous complication should be kept in mind during the halo vest fixation.