Purpose: Introduction to the ophthalmic literature of an unusual cause of papilledema and subsequent optic atrophy: X-linked hypophosphatemic rickets (XLH). Methods: Case report of a 3-year-old female presenting with papilledema resulting from craniosynostosis secondary to XLH. Results: Early intervention with craniofacial surgery prevented the development of optic atrophy. Conclusion: Children with XLH should be screened for ophthalmic evidence of elevated intracranial pressure to aid early intervention and prevention of permanent loss of vision