IL-17 is a novel cytokine that is characterized by an ability to induce several types of cells to secrete proinflammatory cytokines in various inflammatory diseases. This study analyzed the influence of IL-17F gene polymorphisms on disease susceptibility and clinical features. Ninety-nine Behçet's disease (BD) patients and 114 controls were genotyped to analyze three single nucleotide polymorphisms (SNPs) including A126G, G155A, and A161G of the IL-17F gene using automated sequencing. We compared the frequencies of IL-17F alleles, genotypes, and haplotypes in patients with BD and controls using the chi-square or Fisher's exact test. Significant differences in the frequencies of allele and genotype in A126G SNP of IL-17 gene were found between BD patients and controls (P<0.001 and P<0.001, respectively). None of three IL-17F SNPs were associated with diverse clinical features in BD. The frequency of haplotype AA did not differ between patients with BD and controls (P=0.985). The haplotypes, AG, and GG, have positive and inverse association with BD susceptibility (P<0.001 and P<0.001, respectively). These findings suggest that IL-17 gene SNPs may influence the susceptibility of BD.