Craniofacial syndromes are a diverse group of congenital disorders primarily affecting structures of the head and face. Recent genetic advances have improved our ability to diagnosis specific syndromes, understand the molecular basis for abnormal embryogenesis, and anticipate future treatment needs. This is the first of a two-part series exploring the most common craniofacial disorders. This article will provide the embryologic and developmental foundation necessary to understand congenital craniofacial pathology. Clinical characteristics and molecular genetics needed to make an accurate diagnosis and formulate a treatment plan will be detailed for craniosynostosis syndromes, craniofacial microsomia, and craniofacial dysostoses. This review contains 13 figures, 4 tables, and 42 references. Keywords: craniofacial embryology, craniofacial growth, craniosynostosis, Apert syndrome, Crouzon syndrome, Pfieffer syndrome, craniofacial microsomia, hemifacial microsomia, Treacher Collins syndrome, Nager syndrome