A case of cranio-facial dysostosis of Crouzon occurring in a 4 year old girl is described. The family tree of this patient is of particular interest because the deformity is known to have been present in 10 members of four generations, thus demonstrating the hereditary nature of the malformation. Because 10 of the 21 progeny were afflicted, the pedigree is interpreted as meaning that the disorder is the expression of an heterozygous, dominant trait. The patient was considerably benefited by the operation advocated by Faber and Towne for premature cranial synostosis, as modified by Ingraham.