We retrospectively reviewed the medical records of 604 meningitis patients from the emergency department (ED) of our tertiary care, university-affiliated hospital over a five-year period. We analyzed the ability of blood PCT levels on admission to predict the outcome at discharge (defined as Glasgow Outcome Scale scores of 1–4). Of 71 patients with acute bacterial meningitis, 28 (39 %) experienced an unfavorable outcome at discharge (overall mortality: 5 %). The serum PCT level at admission was a predictive indicator of an unfavorable outcome [adjusted odds ratio: 1.04, 95 % confidence interval (CI) 1.01–1.09, p = 0.05]. As assessed using receiver operating characteristic curves for an unfavorable outcome, the area under the PCT curve was 0.708 (95 % CI 0.58–0.84, p less than 0.01). When the PCT cutoff value was greater than or equal to 1.10 ng/mL, the sensitivity, specificity, positive predictive value and negative predictive value for an unfavorable outcome were 75, 70, 62, and 81 %, respectively. An association between the serum PCT level and an unfavorable outcome is observed.