We reported an 83-year-old woman, who suffered from bacterial meningitis and subsequent vasculitis. She experienced episodes of loss of consciousness several times in July, 2006. She also had recurrent fever and was admitted to a local hospital. Routine examinations, including brain MRI and electroencephalogram, were negative and urinary tract infection was diagnosed. After successful antibiotic therapy, she was transferred to a rehabilitation hospital. After transfer, she had no headache, but presented fever again, and a reduced level of consciousness. Cerebrospinal fluid test showed that cell counts were high with a predominance of neutrophils, and her glucose level was low. She received antibiotic therapy on her suspicion of bacterial meningitis. Bacterial cultures of CSF and blood were negative, probably due to the previous antibiotic therapy. Repeated CSF analysis showed a decrease in cell counts, but her lower consciousness did not improve. Moreover, neurological symptoms such as left pyramidal tract sign appeared. She was transferred to our hospital on the suspicion of vasculitis. Diffusion MRI showed high intensity in the right middle cerebral artery (MCA) area and CT angiography showed the stenosis of the right MCA at the M3 portion. Two courses of steroid pulse therapy were performed. Her consciousness gradually improved and eventually could talk although cognitive decline remained as a residual deficit. Our patient failed to be diagnosed early because of atypical symptoms of meningitis. Caution seems necessary for elderly cases presenting with atypical initial symptoms of meningitis. Steroid pulse therapy was effective for the subsequent vasculitis, as reported previously.