Some studies have suggested that the Toll-like receptor 9 polymorphism (TLR9 rs352140) is closely related to risk of bacterial meningitis (BM). but this is subject to controversy. This study set out to estimate whether the TLR9 rs3 52140 polymorphism confers an increased risk of BM. Relevant literature databases were searched including Pubmed. Embase. the Cochrane libraiy. and China National Knowledge Infrastructure (CNKI) up to August 2020. Seven case-control studies from four publications were enrolled in the present meta-analysis. Odds ratios (OR) and confidence intervals (95%CI) were calculated to estimate associations between BM risk and the target polymorphism. Significant associations identified were, allele contrast (A vs. G: OR=0.66. 95%CI=0.59-0.75, P=0.000)? homozygote comparison (AA vs. AG/GG: OR=0.62. 95%CI=0.49-0.7S, P=0.000). lieterozygote comparison (A vs. G: C>R=0.74, 95%C'I=0.61-0.9L P=0.005). recessive genetic model (AA vs. AG/GG: OR=0.78, 95%CI=0.65-0.93. P=0.006) and dominant genetic model (AA vs. AG/GG: OR=0.70. 95%CI=0.57-0.85. P=0.0C)). The findings indicate that, in contrast to some studies, the TLR9 rs352: Olymorphism is associated with a decreased risk for BM. © 2020 Lippincott Williams and Wilkins. All rights reserved.