BackgroundAseptic meningitis is a relatively frequent childhood disease and virologic data suggest that enteroviruses are the commonest etiologic agents. We evaluated the epidemiologic characteristics of aseptic meningitis in Daejeon, South Korea from 1987 to 2003.Methods2201 medical records of children with aseptic meningitis admitted to The Catholic University of Korea, Daejeon St Mary's Hospital were retrospectively analyzed.ResultsOutbreaks of aseptic meningitis were observed in 1990, 1993, 1996, 1997, 2001 and 2002. The age distribution of cases was relatively uniform, with a higher incidence in those aged <1 year and 4–7 years. The male-to-female ratio was 2:1. There was a higher incidence of disease in the summer (May to August, 74.1% of total). Comparison of the largest epidemics in 1997 and 2002 showed significant differences in the incidence in those <1 year (11.8% vs. 4.4%, respectively; P = 0.001). Neurologic sequelae were observed in 0.7% of the patients.ConclusionAseptic meningitis, rare before the 1980s in Korea, has since become a common clinical entity. Since 1990, outbreaks of aseptic meningitis have occurred every 1 to 3 years in Daejeon in keeping with Korea-wide epidemics. The frequency of disease affecting children less than one year of age may reflect herd immunity to the epidemic strain.