Medical data for 55 cervical spine injury victims of auto accidents seen over the last 7 years were reviewed. Particular attention was taken of the associated head injury. Twenty-nine patients had altered states of consciousness though usually transient. Three mechanisms of injury were defined each associated with a particular type of head injury. Injuries to the face produced head and neck extension and subjected the cervical spine to tension, i.e., extension-tension fractures. The most common fracture in this group was the "Hangman's" fracture seen only in judicial hangings and auto accidents. Injuries to the forehead and frontal regions produced head and neck extension and subjected the cervical spine to compression, i.e., extension-compression fracture. Posterior small parts fractures including a fracture of an inferior facet was usually seen. Injury to the parieto-occipital regions produced head flexion and subjected the cervical spine to compression, i.e., flexion-compression fracture. This mechanism resulted in wedge and burst fractures of the lower cervical vertebral bodies and anterior dislocations. The first two mechanisms seldom produced neurological deficit while the third frequently resulted in a transverse myelitis. Odontoid fractures do not fit into any of the groups noted and are discussed separately. Careful examination of an accident victim's head should be carried out looking for clues indicative of an associated cervical spine injury. Routine cervical spine x-rays should be obtained on all auto accident victims with head injuries who are not fully lucid or who complain of neck pain.