To examine the genetic polymorphisms in the promoter region of cyclooxygenase-2 ( COX-2) and evaluate their association with the risk of gastric cancer.Single-strand conformational polymorphism and DNA sequencing were used to screen the genetic variants of the COX-2 promoter region. Total 323 patients with gastric cancer and 646 frequency-matched controls were genotyped by polymerase chain reaction-restriction fragment length polymorphism method. Odds ratios (OR) and 95% confidence intervals (CI) were estimated by logistic regression. Haplotype frequency was estimated using Haplo. stat software.Three single nucleotide polymorphisms, including - 1290A > G, -1195G > A, and -765G > C were identified in the promoter of COX- 2. Case-control analysis showed an increased risk of developing gastric cancer for the -1290AG (OR 1.64; 95% CI 1.03-2.61), -1195AA (OR 2.68; 95% CI 1.65-4.33), and -765CG (OR 2.66; 95% CI 1.53-4.64) genotype carriers, respectively, compared with noncarriers. A greater risk of developing gastric cancer was observed for the A(-1290) -A(-1195) -C(-765) haplotype compared with the A(-1290) -G(-1195) -G(-765) haplotypes (OR 11.80; 95% CI 2.43-57.25).Genetic polymorphisms in COX-2 promoter region may play a role in gastric carcinogenesis.