In the overall analysis, we did not find significant association between IL-18 −607C/A polymorphisms and the risk of allergic disease under all models (A allele versus C allele: OR = 1.03, 95% CI = 0.91–1.15, P = 0.67; AA + AC versus CC: OR = 1.02, 95% CI = 0.85–1.22, P = 0.86; AA versus AC + CC: OR = 1.07, 95% CI = 0.88–1.28, P = 0.51; AA versus CC: OR = 1.01, 95% CI = 0.77–1.33, P = 0.94; AC versus CC: OR = 1.00, 95% = 0.83–1.21, P = 0.98, Figure 2). Here, IL18 is linked to allergic disease.