To evaluate the role of interleukin (IL)-8 in meningococcal disease, a solid-phase double-ligand ELISA was used to quantitate IL-8 in sera and cerebrospinal fluid (CSF) from patients with meningococcal meningitis, bacteremia, or both with or without septic shock. IL-8 was demonstrated in sera from 28 of 62 patients; levels were significantly higher in patients with septic shock without meningitis (median, 36.1 ng/mL) than in patients with other manifestations (median, < 0.02 ng/mL), and 4 of 5 patients who died had high levels. IL-8 was detected in all 27 CSF samples. Serum IL-8 levels correlated highly significantly with those of IL-6 (r = .83) and tumor necrosis factor (TNF; r = .64), while the correlations between corresponding CSF levels were less pronounced (r = .43 and r = .38, respectively) but still significant. Serum IL-8 levels were highest in patients with a symptom history < 12 h. The elimination rate of IL-8 from serum varied and was similar to that of IL-6 and TNF. IL-8 appears to participate in the complex cytokine network during the initial phase of systemic meningococcal infections.