A 57-year-old woman had undergone surgery for meningioma. After the surgery, she suffered from repeated fever and headache. One year after surgery, she was admitted to our hospital for further examination. Cerebro-spinal fluid (CSF) findings indicated bacterial meningitis infection. Germ culture, acid-fast bacterium culture, PCR for mycobacteriosis and cryptococcus antigens as well as cytological examination of CSF were checked repeatedly. However, all examinations were negative and etiology was unknown. We treated with many anti-bacterial, anti-fungal and anti-tubercular drugs, but CSF findings were not improved. We repeated CSF examination and finally Mycobacterium fortuitum (M. fortuitum) was isolated. Clarithromycin (CAM) was started for M. fortuitum meningitis. After drug sensitivity testing, levofloxacin (LVFX), which was effective against M. fortuitum, was added to CAM, after which clinical and CSF findings improved dramatically. M. fortuitum rarely causes CNS infection. Several English literatures on M. fortuitum meningitis after traumatic injury and surgery have been published. Its CSF findings distinctly resemble those of bacterial meningitis, but are resistant to the usual antituberculosis drugs. We reported a case of M. fortuitum meningitis associated with surgery for meningioma.