PURPOSE: The etiology of febrile seizures is not yet ascertained but it is known that genetic factors, cytokines or trace elements are associated with pathogenesis of febrile seizures. Among them, zinc deficiency is known to play some role of pathogenesis of febrile seizures. We purposed to know the relation between recurrence of febrile seizures and serum zinc level. METHODS: The subjects were recurrent febrile seizures group who were admitted to our hospital from June 2003 to July 2005 because of more than 3 times febrile seizures. The other two control groups were simple febrile seizures and acute febrile illness groups admitted to our hospital in same period. Simple febrile seizures group showed no more seizure over 1 year after first onset. We investigated serum zinc level in each group. RESULTS: The number of patient in each group is 33 children. Recurrent febrile seizures group was composed of 20 boys and 13 girls (the ratio of 1.5:1) with an average age 30 months old. The mean serum zinc levels in the recurrent febrile seizures group (123.7+/-9.6 microgram/dL) were not statistically different from those of the simple febrile seizures group(112.5+/-8.9 microgram/dL). Both of the recurrent and simple febrile seizures groups had significantly lower serum zinc levels than the febrile illness group(154.1+/-6.8 microgram/dL). CONCLUSION: We suggested that serum zinc level is not relationship with recurrence of febrile seizures. Nevertheless, the fact remains that serum zinc level was decreased in recurrent and simple febrile seizures groups compared with acute febrile illness group.