We demonstrated that IL-18 gene promoter −607 C>A polymorphism was associated with a statistical increased risk of cancer susceptibility in the variant CA heterozygote and CA/AA genotype compared with the CC wild type homozygote, especially in nasopharyngeal carcinoma and gastrointestinal cancer, however, an opposite trend was found in genitourinary system cancer. This evidence concerns the gene IL18 and nasopharyngeal carcinoma.