Interleukin-4 (IL-4) is a cytokine with anti-inflammatory properties. This study was undertaken to investigate whether IL-4 intron 3 gene polymorphism could be used as markers of susceptibility to febrile seizures and epilepsy of children. Children were divided into three groups: group 1, febrile seizures (n = 51); group 2, epilepsy (n = 43); and group 3, normal control group (n = 83). Polymorphisms for IL-4 intron 3 were detected by polymerase chain reaction. Genotypes and allelic frequencies for IL-4 intron 3 gene polymorphism in three groups were compared. We found that proportions of different IL-4 intron 3 polymorphisms in three groups were nonsignificantly different. Proportions of RP1 homozygote/heterozygote/RP2 homozygote for IL-4 intron 3 in three groups were as follows: group 1, 56.9/41.2/1.9%; group 2, 62.8/32.6/4.6%; and group 3, 62.7/33.7/3.6%. The proportion of RP1/RP2 for IL-4 intron 3 in three groups were as follows: group 1, 77.5/22.5%, group 2, 79.1/20.9%, and group 3, 79.5/20.5%. We concluded that the association of IL-4 polymorphisms with febrile seizures and epilepsy of children does not exist. IL-4 intron 3 polymorphism is not a useful marker for prediction of the susceptibility of febrile seizure and epilepsy of children.