Ventriculoscopy represents a new concept in the surgical treatment of children with hydrocephalus. Optimal catheter position can now be achieved with the help of a new method consisting of endoscopically controlled implantation of ventricular shunts. In addition, interventional ventriculoscopy enables or improves new operative procedures such as the fenestration of intracranial cysts or the removal of dislodged parts of catheter tips from the corresponding ventricle under direct optical control. Ventriculoscopy has been performed on 17 pediatric patients, with no complications to date. Copyright (C) 1995 by W.B. Saunders Company.