A craniofacial condition involves both the cranium, with its contents, and the face. Craniosynostosis is the premature fusion of cranial sutures. The overall prevalence of craniosynostosis has been estimated at between 1 in 2100 and 1 in 2500 live births. It is most often an isolated finding, affecting the sagittal or coronal sutures, but can also occur as part of a syndrome, with additional findings such as limb abnormalities and developmental delay. It is termed ‘simple’ synostosis if a single suture is involved. All multiple suture synostoses (‘complex’ cases) are syndromic. More than a hundred syndromes associated with craniosynostosis have been described. The commoner ones are described in this chapter.