Adult periodontitis is a multifactoral disease characterized by multiple genetic and environmental factors. In view of the importance of interleukin-4 (IL-4) gene as a genetic factor for adult periodontitis, we investigated the relationship between two polymorphisms (-590 C --> T polymorphism and 70 bp repeat polymorphism) of the human IL-4 gene and adult periodontitis in the Korean population. Genomic DNA was extracted from white blood cells of 32 adult periodontitis patients and 150 normal controls, respectively. There were no significant differences in the allele, genotype and haplotype distributions of two polymorphisms between normal controls and adult periodontitis group. Therefore, our results suggest that IL-4 gene locus contributes little to the interindividual susceptibility for adult periodontitis in Korean population.