The aim of the study was to assess adjunctive intravenous dexamethasone in adult community-acquired bacterial meningitis (BM) in daily practice. Analysis of consecutive patients (1990–2009) with acute community-acquired bacterial meningitis in a single centre in Zagreb, Croatia, N = 304. Adjusted relative risks [RR, dexamethasone vs. no dexamethasone (control)] of Glasgow Outcome Scale (GOS) = 1 (death) and GOS = 5 (full recovery) at discharge/end of specific treatment were estimated considering demographics; co-morbidity; BM pathogenesis and on-admission characteristics, and cerebrospinal fluid (CSF) inflammation markers; causative agent and antibiotic use. Two hundred forty (79%) patients had proven BM (43.1% Streptococcus pneumoniae, any other agent ≤8.2%). No independent effects of dexamethasone on GOS = 1 or GOS = 5 were observed in the entire cohort (dexamethasone n = 119, control n = 185; RR = 1.06, 95% CI 0.77–1.45 and RR = 0.99, CI 0.83–1.20, respectively), microbiologically proven disease (dexamethasone n = 104, control n = 136; RR = 0.97, CI 0.69–1.38 and RR = 1.03, CI 0.82–1.28), pneumococcal disease (dexamethasone n = 71, control n = 60; RR = 0.95, CI 0.53–1.70 and RR = 0.82, CI 0.57–1.18), and also in other BM, subgroups based on consciousness disturbance, CSF markers, prior use of antibiotics and timing of appropriate antibiotic treatment. CSF markers did not predict the outcomes. Conclusions: Our experience does not substantiate the reported benefits of adjunctive dexamethasone in adult BM. Socio-economic and methodological factors do not seem to explain this discrepancy. Empirical use of dexamethasone in this setting appears controversial.