Our meta-analysis includes total of 22 studies exhibiting remarkable diagnostic accuracy of CSF-ADA for detecting TBM cases with a sensitivity of 0.85 (95% CI: 0.77-0.90), specificity of 0.90 (95% CI: 0.85-0.93), area under curve (AUC) 0.94 (95% CI: 0.91-0.96), and diagnostic odds ratio 48 (95% CI: 26-86) thus, building it a promising diagnostic test for TBM in adult patients. This evidence concerns the gene ADA and meningeal tuberculosis.