BACKGROUND: There is substantial variation in the reported treatment outcomes for adult tuberculous meningitis (TBM). Data on survival and neurological disability by continent and HIV serostatus are scarce. METHODS: We performed a systematic review and meta-analysis to characterize treatment outcomes for adult TBM. Following a systematic literature search (MEDLINE and EMBASE), studies underwent duplicate screening by independent reviewers in 2 stages to assess eligibility for inclusion. Two independent reviewers extracted data from included studies. We employed a random effects model for all meta-analyses. We evaluated heterogeneity by the I 2 statistic. RESULTS: We assessed 2197 records for eligibility; 39 primary research articles met our inclusion criteria, reporting on treatment outcomes for 5752 adults with TBM. The commonest reported outcome measure was 6-month mortality. Pooled 6-month mortality was 24% and showed significant heterogeneity (I 2 > 95%; P < .01). Mortality ranged from 2% to 67% in Asian studies and from 23% to 80% in Sub-Saharan African studies. Mortality was significantly worse in HIV-positive adults at 57% (95% CI, 48%-67%), compared with 16% (95% CI, 10%-24%) in HIV-negative adults (P < .01). Physical disability was reported in 32% (95% CI, 22%-43%) of adult TBM survivors. There was considerable heterogeneity between studies in all meta-analyses, with I 2 statistics consistently >50%. CONCLUSIONS: Mortality in adult TBM is high and varies considerably by continent and HIV status. The highest mortality is among HIV-positive adults in Sub-Saharan Africa. Standardized reporting of treatment outcomes will be essential to improve future data quality and increase potential for data sharing, meta-analyses, and facilitating multicenter tuberculosis research to improve outcomes.