The clinical features, investigations, treatment and outcome were studied in 104 patients with definite or probable tuberculous meningitis. The diagnosis of definite tuberculous meningitis required the growth of Mycobacterium tuberculosis from cultures, or a positive polymerase chain reaction (PCR) assay for M. tuberculosis. In probable tuberculous meningitis, cultures and the PCR assay were negative, but other causes of meningitis were excluded and there was a response to anti-tuberculosis treatment. Of the 104 patients, 36% had a poor outcome (severe disability, persistent vegetative state or death), 12% moderate disability and 52% good recovery. A diagnosis of definite tuberculous meningitis, the severity of the symptoms at presentation and the occurrence of a stroke were significant predictors of a poor outcome. The most common reasons for a delayed diagnosis were presentation with mild symptoms wrongly attributed to a systemic infection, incorrectly attributing CSF abnormalities to non-tuberculous bacterial meningitis and failure to diagnose extraneural tuberculosis associated with meningitis. Recognition of the difficulties in making a diagnosis of tuberculous meningitis may facilitate earlier diagnosis in the future.