Objectives: Based on anatomical knowledge of the upper cervical spine, it is necessary to be familiar with the classification, diagnosis, and treatment strategies currently used clinically for upper cervical spine injuries. Summary of literature review: Upper cervical spine injuries are major injuries with potentially fatal consequences. The occipitocervical junction, which is composed of several structures, protects the brain and cranial nerves. We need to know the mechanism of each type of damage, and in particular, we must understand the anatomy of the occiput, atlas, and axis, as well as the definitions of landmarks of the positional relationships among all structures. Materials and methods: This study reviewed the latest literature on upper cervical spine injuries. Results: In occipital condyle fractures and atlanto-occipital injuries, we should understand how to evaluate instability and the treatment methods according to each classification. In atlas injuries, it should be evaluated whether the transverse atlantal ligament has been damaged. In axis fractures, it is necessary to understand the surgical method according to the shape of the odontoid fracture. Conclusions: Knowledge of soft tissue and bony structural relationships in the upper cervical spine is required for the diagnosis and treatment plan of upper cervical injuries.