We report an unusual case of fusobacterial infection with secondary intracranial invasion. The condition was complicated by a cavernous sinus thrombosis and ischemic stroke. The patient was a 63-year-old woman with no history of systemic disease who had undergone a tooth extraction before the onset of symptoms. She initially suffered from sphenomaxillary sinusitis and a cavernous sinus thrombosis, and subsequently developed meningitis. Cerebrospinal fluid examination suggested a pyogenic infection. Anaerobic culture revealed Fusobacterium nucleatum. However, despite immediate antibiotic therapy, her condition remained unstable over the next few days, and she eventually developed an ischemic stroke. We describe our experience in the management of this case of anaerobic meningitis and the unusual complication of ischemic stroke; this case suggests that more aggressive therapy in addition to empirical antibiotics may be warranted.