We investigated the levels of transforming growth factor beta 1 (TGF-beta 1)in cerebrospinal fluid (CSF) in children with meningitis, with a view to prognostic relevance. CSF TGF-beta 1 levels on admission were measured by a sandwich enzyme immunoassay in children with bacterial meningitis (n = 16), aseptic meningitis (n = 12), and control subjects without evidence of central nervous system (CNS) Infection (n = 16). Patients were followed up for a mean duration of 13 months, and neurodevelopmental sequelae was determined for those with bacterial meningitis, On admission, CSF TGF-beta 1 levels were significantly higher in children with bacterial meningitis (mean, standard error, 32.92, 2.36 pg/ml) as opposed to those with aseptic meningitis (25.26, 1.72 pg/ml) (P = 0.0155), or control subjects (20.53, 1.05 pg/ml) (P < 0.0001). The CSF TGF-beta 1 levels in children with aseptic meningitis were higher than those in the control group, but without significance (P = 0.02). No apparent correlation existed between CSF TGF-beta 1 levels and CSF protein or cell counts in patients with bacterial meningitis, No significant difference in CSF TGF-beta 1 levels was found between patients with or without major sequelae following bacterial meningitis.