BACKGROUND: Rapid and accurate detection of Mycobacterium tuberculosis is important for patients with tuberculous meningitis because early diagnosis and prompt initiation of treatment improve the outcome of the disease. PCR techniques have been applied but are not yet well established for the diagnosis of tuberculous meningitis. The Amplicor(TM) M. tuberculosis test (Roche Diagnostic Systems, Inc. ) can be used fur the detection of M. tuberculosis by PCR technique, but its use has not been recommended currently for extrapulmonary samples. We evaluated the Amplicor(TM) M. tuberculosis test for the direct detection of M. tuberculosis from cerebrospinal fluid (CSF) specimens of patients suspicious of having tuberculous meningitis. METHODS: We examined a total of 103 CSF samples from 76 patients. Tuberculous meningitis was diagnosed by clinical history, chest X-ray, CSF chemistry, bacteriology, computed tomography and response to antituberculous treatment. Twenty-six samples were obtained from 13 patients with tuberculous meningitis. For the Amplicor(TM) M. tuberculosis test, 0.3 - 2.0 mL of CSF was centrifuged at 15,000 rpm for 15 min and its pellet was treated as the instructions of the kit. RESULTS: Of the 103 CSF samples, none were smear-positive by Ziehl-Neelsen acid-fast stain, seven were culture-positive and twelve were PCR-positive. Of the 26 samples from 13 patients with tuberculous meningitis, seven from six patients were culture-positive and eleven from six patients were PCR-positive. The sensitivity, specificity, positive and negative predictive values of the Amplicor(TM) M. tuberculosis test for the patients compared to the clinical diagnosis were 46.2, 98.4, 85.7, and 89.9%, respectively, while the culture yielded 46.2, 100.0, 100.0, and 90.0%, respectively. CONCLUSIONS: The Amplicor(TM) M. tuberculosis test using CSF specimen for the diagnosis of tuberculous meningitis is specific and is as sensitive as culture. The assay will provide rapid and valuable information for the diagnosis and control of tuberculous meningitis.