ObjectiveTo systematically review the association between -765 G > C (rs20417) polymorphism of cyclooxygenase-2 (COX-2) gene and the risk of gastric cancer (GC). MethodsSuch databases as PubMed, EMbase, The Cochrane Library (Issue 10, 2015), CBM, CNKI, VIP and WanFang Data were searched from inception to October 2015 to collect case-control studies about the correlation between -765 G > C (rs20417) polymorphism of COX-2 gene and GC. Two reviewers independently screened literature, extracted data and evaluated the quality of included studies. Meta-analysis was performed using Stata 12.0 software. ResultsA total of 15 case-control studies were included in this meta-analysis, including 2 891 cases and 4 967 controls. Meta-analysis showed that the -765 G > C (rs20417) polymorphism was significantly associated with the risk of GC (OR=1.70, 95%CI 1.21 to 2.38, P=0.002). Subgroup analysis showed there was a significant association between the -765 G > C (rs20417) polymorphism and GC in Asians (OR=2.24, 95%CI 1.70 to 2.96, P=0.000); However, no association was found in the Caucasians and Americans. In the subgroup analysis by Helicobacter pylori (H. pylori) status, there were statistical significances between helicobacter pylori (+) and helicobacter pylori (-) with the risk of GC in COX-2 polymorphism of CC/CG vs. GG (OR=2.11, 95%CI 1.41 to 3.14, P < 0.001). ConclusionThe COX-2-765 G > C (rs20417) polymorphism may be significantly associated with an increased risk of GC, especially among Asians.