There is evidence suggesting that inflammation plays an important role in the pathogenesis of intracranial aneurysms (IAs). Interleukin-6 (IL-6) is an important pro-inflammatory cytokine, and some authors have demonstrated that IL-6 promoter polymorphism -572G > C is associated with IAs in Caucasian population. We performed a case-control study to investigate whether this single nucleotide polymorphism (SNP) might affect the development of IAs in Chinese Han population. The study groups comprised 240 Chinese Han nationality aneurysmal patients and 240 controls. Differences in genotype and allele frequencies between patients and controls were tested by the chi-square method. The results showed that among the Chinese Han subjects, there were significant differences in genotypic distribution and allele frequencies between aneurysmal patients and controls. The GG genotype was significantly more common in patients than in controls (24.5% vs. 3.7%, p < 0.001, odds ratio 8.366, 95% CI: 4.040-17.324), and the G allele was much more frequent in patients than in controls (51.7% vs. 20.8%, p < 0.001, odds ratio 4.062, 95% CI: 3.058-5.395). (C) 2008 Elsevier Ireland Ltd. All rights reserved.