Growing skull fractures are reported in three infants undergoing cranial vault surgery for craniosynostosis. Although primary dural injury was overt in only one patient, an extensive dural defect with spatially coincident bony absence was identified in all patients at late exploration. The coincidence of dural injury, deficient overlying bone, and a pulsatile growing brain are necessary conditions for the development of growing skull fractures. With the advent of increasingly radical cranial vault procedures during infancy, the potential for this complication to arise may increase. Definitive correction requires autogenous tissue reconstruction of the dural and bony defect.