Craniosynostosis describes the premature pathologic partial or complete fusion of 1 or more of the cranial sutures. Over the past few decades, research on craniosynostosis has progressed from gross description of deformities to an understanding of some of the molecular etiologies behind premature suture fusion. Studies on patients with syndromic craniosynostosis have resulted in the identification of several genes, molecular events, and deformational forces involved in abnormal growth and development of the cranial vault. Conservation of craniofacial development and sequence homology between humans and other species have also led to insightful discoveries in cranial suture development. In this review, we discuss the development of the cranial vault and explain the basic science behind craniosynostosis in humans as well as in animal models and how these studies may lead to future advances in craniosynostosis treatments.