The objective was to identify risk factors for shunt infections, and establish the rate of infection for shunt procedures carried out under standardized conditions in a well-defined population. All (407) paediatric, shunt operations (primary and revisions) performed within a total population of 630 000 inhabitants between January 1, 1986 and December 31, 1996, were analysed retrospectively. I I shunt infections were diagnosed in 10 patients, giving an overall infection rate of 2.7% per procedure and 6.2% per patient. Infections were significantly correlated with age, type of operation, and a etiology of hydrocephalus. Thus, infections occurred more frequently during the first 6 months of life, more often following primary shunt insertions compared with revisions, and children with myelomeningocele had a higher infection risk than children with hydrocepitalus due to other causes. There was a highly significant male preponderance in the patient material. Conclusion. The overall infection rate was relatively low. The risk factors for shunt infections appear to relate to epidemiological characteristics rather than to surgical factors.