Craniocervical junction kyphosis is considered as a structural kyphotic angulation of the region between the clivus and odontoid. This region is a structurally stable structure composed of bone and connective tissue. The importance of this region is because it is the transition zone between the spinal cord and the brain. The junction region is responsible for transferring the weight of the head to the cervical area and ensuring its stability. Many anomalies of this region can cause craniocervical junction kyphosis. Tumours, infections and traumatic injuries may also be associated with junctional kyphosis. In this chapter, we will discuss the most common structural causes of craniocervical junction kyphosis in practice, namely basilar invagination and Chiari malformation.