Intraventricular chemotherapy is increasingly used in the treatment of pediatric brain tumors with leptomeningeal seeding. However, some patients are shunt dependent after surgery, probably due to adhesions in the area of surgery. To avoid drug diversion in these patients we connected the reservoir to a reversible occlusion device. Over a 2-year period a shunt value with an on-off device was inserted into the shunt assembly of eight children with various brain tumors with a poor prognosis undergoing intraventricular chemotherapy. All eight patients had tumor cells in the ventricular cerebrospinal fluid (CSF) and/or metastases by magnetic resonance imaging. The number of intraventricular drug applications ranged from 10 to 51. No shunt malfunctions or shunt-related infections occurred. The temporary closure of the shunt after drug delivery was well tolerated. In all six children with tumor cells in the ventricular CSF a negative cytology was achieved over a 3- to 8-week period.