Purpose: Very long-term follow-up and outcome are rare for pediatric patients with hydrocephalus and shunt operations. The aim of this study was to determine the long-term mortality rates in these patients. Methods: Pediatric patients with first shunt operation between 1982 and 1992 were included. For each patient, time and cause of death were determined. Further, patients with first operation from 1982 to 1987 were compared to those first operated from 1988 to 1992. Results: One-hundred thirty-seven patients were included. Etiologies of hydrocephalus were intraventricular hemorrhage (31.4 %), meningomyelocele (25.5 %), postinfectious (11.7 %), congenital (10.2 %), posterior fossa cyst (8.8 %), aqueductal stenosis (8 %), and others (4.4 %). Overall, 53 patients (38.7 %) died. The percentage of patients surviving 1, 2, 10, and 20 years after first operation were 82.6, 73.6, 69.4, and 65.3 %, respectively. In 23 patients, the cause of death was related to shunt treatment: shunt infection was diagnosed in 18 and acute shunt dysfunction in 5 patients. Mortality was considerably higher for patients with their first operation in time period 1982–1987 compared to time period 1988–1992 (51 versus 25 %). The reduction of mortality was mainly due to an increased survival after shunt infection. Eighty-seven patients survived more than 20 years after initial shunt operation. Of those long-term survivors, three (3.4 %) patients died 22–24 years after first operation. Conclusion: Mortality in hydrocephalic pediatric patients is high especially in the first postoperative years but is even significant in adult patients with pediatric hydrocephalus. As deaths occur even after 20 years, routine follow-up of long-term survivors remains necessary.