Tuberculosis is hyperendemic in Niger. In Niamey between June 2002 and May 2004, 996 cerebro-spinal fluids (CSF) collected from meningitis suspected patients have been analysed by PCR for the detection of Neisseria meningitidis, Haemophilus influenzae and Streptococcus pneumoniae: the aetiologic diagnosis was obtained for 208 cases (20.9%). The Mycobacterium tuberculosis PCR assay performed on the negative samples was positive for 4 CSF: 0.4% prevalence among suspected cases of meningitis or 1.9% among confirmed bacterial meningitis.