Data on 233 children with congenital hydrocephalus who were operated on in our department from 1964 to 1984 were analyzed. The study was started in January 1990 and was based on questionnaire followed by a psychological examination. Thirty-two patients (13.7%) died during the follow-up period. The average number of operations during the observation period was 2.7; in 166 patients (= 71.2%) the shunt had to be revised at least once. The reason for revision was a mechanical problem in 79.4% and infection in 15.5%. The psychological evaluation in 115 patients showed a normal performance in 62.8%, while 29.8% had mild retardation, evident in speech impairment and/or impaired speech development, in memory and concentration, in poor intellectual performance and decreased performance in school. Severe retardation was seen in 7.4% of cases. Our results showed that the best outcome can be achieved with early shunt implantation. We did not, however, find any correlation between shunt revision rate and psychological results.