Streptococcus oralis is part of the normal flora of the oropharyngeal, nasal, gastrointestinal and genitourinary tracts. Classically, it shows low pathogenicity and virulence, but can very rarely cause meningitis in patients who have undergone dental procedures and have poor oral hygiene. The purpose of this report is to highlight the importance of considering S. oralis as a cause of meningitis in patients with poor oral hygiene. A 53-year-old man was admitted to the emergency department with high fever (39.4°C), headache and drowsiness. His mouth was unhygienic. He was diagnosed with meningitis and empiric antibiotics (ceftriaxone plus ampicillin) and dexamethasone were started. S. oralis was isolated from cerebrospinal fluid. Ampicillin and dexamethasone were stopped, while ceftriaxone was continued with full recovery of the patient.