Objective To compare relative efficacy of different antibiotic therapies either with or without the addition of corticosteroids among adult patients with acute bacterial meningitis on all-cause mortality, neurological complications and any hearing loss. Methods We searched nine databases from inception to 8 February 2018 for randomized controlled trials evaluating pharmacological interventions and clinical outcomes in adult bacterial meningitis. An updated search from 9 February to 9 March 2020 was performed, and no new studies met the inclusion criteria. Study quality was assessed using the revised Cochrane Risk of Bias Tool. The Grading of Recommendations Assessment, Development and Evaluation system was used for quality of evidences evaluation. Meta-Analyses were conducted to estimate the risk ratio with 95% confidence interval for both direct and indirect comparisons on the primary outcomes of all-cause mortality, neurologic sequelae and any hearing loss. The study was registered in PROSPERO (CRD42018108062). Results Nine RCTs were included in systematic review, involving 1,002 participants with a mean age ranging between 25.3 to 50.56 years. Six RCTs were finally included in the networkmeta analysis. No significant difference between treatment was noted in meta-Analysis. Network meta-Analysis suggests that corticosteroids in combination with antibiotic therapy was more effective in reducing the risk of any hearing loss compared to mono antibiotic therapy (RR 0.64; 95%CI, 0.45 to 0.91, 4 RCTs, moderate certainty of evidence). Numerical lower risk of mortality and neurological complications was also shown for adjunctive corticosteroids in combination with antibiotic therapy versus mono antibiotic therapy (RR 0.65; 95% CI, 0.42 to 1.02, 6 RCTs, moderate certainty of evidence; RR 0.75; 95%CI, 0.47 to 1.18, 6 RCTs, moderate certainty of evidence). No differences were noted in the adverse events between different therapies. The overall certainty of evidence was moderate to very low for all primary outcomes examined. Conclusions Results of this study suggest that corticosteroids therapy in combination with antibiotic is more effective than mono antibiotic therapy in reducing the risk of any hearing loss in adult patients with acute bacterial meningitis. More well-design RCTs to investigate relative effective treatments in acute bacterial meningitis particularly in adult population should be mandated to aid clinicians in treatment recommendations.