Polymorphisms in cytokine genes may contribute to increased susceptibility to different cancers. The aim of this paper is to investigate the association of IL-8-251A/T polymorphism and Helicobacter pylori (H. pylori) infection with the risk of developing gastric cardiac adenocarcinoma (GCA) in the south of Taihang Mountain, a high-incidence area of esophageal cancer in China. The IL-8-251 A/T polymorphism was genotyped in 519 cases of GCA and 504 healthy controls. The H. pylori infection in GCA patients and controls was detected by rapid urease test (RUT), histopathology or C-14-urea breath test (C-14-UBT). The results showed that family history of upper gastrointestinal cancer (UGIC) and H. pylori infection significantly increased the risk of developing GCA. The overall genotype and allelotype distributions of IL-8 promoter SNPs in GCA patients were significantly different from those in healthy controls. Compared with TT genotype, AA genotype significantly elevated the risk of developing GCA. The stratification analysis revealed that, compared with the TT genotype, the AA genotype significantly elevated the risk of developing GCA in both positive family history of UGIC and H. pylori infection subgroups. This study provides evidence to support a relationship of increased susceptibility to GCA in individuals of the south Taihang Mountain region with IL-8 251 AA genotype, especially for those individuals who have family history of UGIC or H. pylori infection.