The clinical presentation and course of tuberculous meningitis in 21 patients treated between 1970 and 1983 are analyzed. Tuberculous meningitis may present as acute, subacute, or chronic meningitis. Although characteristic cerebrospinal fluid findings of lymphocytic pleocytosis, low glucose level, and elevated protein level occur in the majority of cases, there are many atypical presentations. The protein level, glucose level, and white blood cell count may be normal, and there may be a predominance of polymorphonuclear cells rather than lymphocytes in the cerebrospinal fluid. Poor prognostic factors in this series were age greater than 65, underlying diseases, and stage 3 presentation. Incorrect or inadequate therapy had a disastrous outcome. Nontuberculous mycobacteria rarely are involved in central nervous system disease. Tuberculous meningitis must be considered in the differential diagnosis of any patient with fever and change in sensorium. A deteriorating mental status and falling cerebrospinal fluid glucose level in the presence of negative findings on bacterial culture and india ink preparation should lead to strong consideration for empiric initiation of anti-tuberculous therapy.