Three children had hydrocephalus associated with myelomeningocele and the Arnold-Chiari malformation. They all experienced neck pain and opisthotonos, followed by the sudden onset of respiratory arrest as a result of the malfunction of a CSF shunt. There were no changes in pupillary response, and each patient remained alert until shortly before the respiratory arrest. Prompt surgical revision of the CSF shunt was carried out, and all three patients recovered. The mechanism of acute respiratory arrest seems to be acute compression of the brainstem as a result of hydrocephalus. The supratentorial pressure is direct on the posterior fossa structures through the enlarged tentorial opening, which is one of the characteristics of the brain in the Arnold-Chiari malformation. Sudden respiratory arrest, a life-threatening complication, is a result of a malfunction of the CSF shunt in children with myelomeningocele and requires prompt surgical decompression.