Endoscopic third ventriculostomy (ETV) was performed between July 1978 and July 1995 on 69 patients with hydrocephalus and myelomeningocele. Most of the patients had been previously shunted, although in 14 patients ETV was the initial treatment. Patient selection was based on preoperative imaging studies suggesting noncommunicating hydrocephalus. Only 2 patients exhibited transient hypothalamic dysfunction with complete resolution. Patients were assessed by their clinical status, imaging characteristics, and, in some cases, formal psychometric studies. The overall success rate was 72%, although selecting only patients who have been previously shunted or who were over 6 months of age at the time of endoscopy increases this to 80%. Our results indicate that ETV is a safe and effective means of treating hydrocephalus in the older spina bifida population and offers the hope of long-term, shunt-independent life for selected patients.