ABSTRACT: OBJECTIVE:Previous studies have reported an association between cyclooxygenase-2 (COX-2) polymorphism and gastric cancer (GC) susceptibility, but their results are controversial. This meta-analysis was intended to evaluate the relationship between the COX-2 rs20417 polymorphism and GC susceptibility in different ethnic groups. METHODS:We searched PubMed, EMBASE, Web of Knowledge, and the Chinese Biomedical Database (CBM) for relevant case-control studies published up to October 6, 2018, which reported an association between the COX-2 rs20417 polymorphism and gastric cancer risk. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of this association. RESULTS:15 papers detailing case-control studies were included in the analysis, which included a total of 2848 GC cases and 4962 healthy controls. The meta-analysis results indicated that the COX-2 rs20417 polymorphism was associated with increased GC susceptibility under allele (G vs C: OR?=?1.67, 95%CI?=?1.19-2.35, P?=?.003), heterozygous (GG vs CG: OR?=?1.44, 95%CI?=?1.03-2.02, P?=?.034), dominant (GC+CC vs GG: OR?=?1.66, 95%CI?=?1.18-2.34, P?=?.004), homozygous (GG vs CC:OR?=?2.20, 95%CI?=?1.07-4.54, P?=?.033), and recessive models (CC vs GG+CG:OR?=?2.05, 95%CI?=?1.09-3.85, P?=?.025). An analysis of ethnic subgroups revealed that the COX-2 rs20417 polymorphism was significantly associated with GC susceptibility in Asians under all 5 models (G vs C: OR?=?2.22, 95%CI?=?1.66-2.96, P?