The medical records of 89 children followed at a multidisciplinary Meningomyelocele Clinic at the Children's Clinics for Rehabilitative Services were reviewed. Almost all children in southern Arizona with meningomyelocele are followed at this clinic. Eight children (foreign nationals) were excluded because they were not eligible for neurosurgery/neurology services at the clinic. The remaining 81 children have been followed at the clinic from 0.25 to 21 years. Seventeen children (21%; age: 1.3-17 years, mean: 9.1 +/- 4.4 years; follow-up: 1.3-16 years) manifested seizures at some time during their course. All children with seizures had shunted hydrocephalus. Neonatal seizures occurred in 2 children currently not receiving medication. An additional 3 children had an acute symptomatic seizure associated with an intraventricular hemorrhage during ventriculoperitoneal shunt revision, 2 of whom later developed epilepsy. Fourteen children (17.3%) had epilepsy; 12 were taking antiepileptic drugs. Seizures were controlled on medication in 5 children. EEG abnormalities were present in 12 children (focal slowing 4, focal spikes 8, diffuse slowing 3, generalized or bilaterally synchronous spike-wave 4). Most of these children (12/14) had evidence of additional central nervous system (CNS) pathology (i.e., areas of encephalomalacia or past stroke 7, cerebral malformations 2, CNS calcifications 1, and frequent apneic spells/cardiac arrest 2). We conclude that epilepsy occurs in approximately 17% of children with meningomyelocele, and most have other CNS pathology to account for their seizures.