Febrile seizure is the most common seizure disorder of childhood. Of the pro-inflammatory cytokines, interleukin-1 is defined as the first endogenous pyrogen. We designed this study to investigate single-nucleotide polymorphisms (SNPs) situated at positions –31 (C/T), and –511 (C/T) of interleukin-1beta (IL-1b) gene promoter and interleukin-1receptor antagonist (IL-1RA) gene variable number of tandem repeats in intron 2 (VNTR); to determine whether these polymorphisms could be a marker of susceptibility to febrile seizures in Egyptian children and we also measured the serum level of IL-1b to assess its relation to such polymorphisms.