A 20-year-old achondroplastic dwarf developed severe papilledema over a short period of time. Since the age of 3 he had a ventriculoperitoneal shunt for presumed hydrocephalus. Severe ventriculomegaly was never documented, neither in the past, nor at presentation. Intracranial pressure was high, and the shunt was obliterated. Despite prompt shunt revision and subsequent bilateral optic nerve sheath decompression the patient developed postpapilledema optic atrophy with bilateral blindness. The pathophysiology of increased intracranial pressure in achondroplasia is discussed.