The Ommaya reservoir facilitates repetitive delivery of drugs into the CSF and is a pharmacologically rational system for intrathecal chemotherapy. Because previous studies have found a high rate of infection and other complications we herein studied our experience with this device. Between 1993 and 2013, 98 children with brain tumors aged 3 months to 21 years (38 ≤ 3 years) had an Ommaya reservoir placed. All patients received perioperative antibiotics. Only specially trained personnel that followed standardized guidelines were allowed to access the reservoir. As of April 2014, 5,472 chemotherapy instillations were performed amounting to a median of 36 deliveries (2-280) per reservoir. Ommaya reservoirs were present for 199,956 days and a median of 1,336 days per device. Median survival of the 52 patients still alive is 7.5 years. Only one patient developed an Ommaya reservoir infection (1 %) that could be temporarily sterilized but eventually required Ommaya reservoir explantation. Early complications related to Ommaya reservoir placement occurred in two patients, in one catheter malposition was corrected intraoperatively and in the other kinking of the catheter at the burr-hole required minor surgical correction. Two delayed complications requiring surgical revision included malpositioning of the catheter tip after rapid shrinkage of the ventricles and disconnection of the ventricular catheter after 24 accesses. No leucodystrophic changes occurred along the catheter track. In conclusion, Ommaya reservoirs are safe and complications infrequent providing that all personnel involved in implanting and subsequently accessing the device are specially trained and pay meticulous attention to strict aseptic conditions.