We report a 43-year-old woman who suffered from Listeria monocytogenes meningitis. She was admitted to our hospital because of headache, nausea, vomiting, and fever. On admission she had no abnormal neurological signs except for severe nuchal stiffness. Cerebrospinal fluid (CSF) examination on the day of admission revealed pleocytosis and increased total protein level. The CSF culture demonstrated Listeria monocytogenes. Because ampicillin therapy was not effective, erythromycin (8 g/day) was added. After 12 hours of erythromycin therapy, the patient complained of moderate hearing difficulty. Erythromycin was then stopped on the next day. Her hearing improved and became normal within 48 hours after discontinuation of erythromycin. Contrast MRI of the brain revealed enhancement of the ependyma of the lateral ventricle, suggesting the presence of ventriculitis. By parenteral administration of ampicillin and cephazolin, clinical symptoms improved quickly, and abnormal CSF and MRI findings were normalized. Listeria meningitis accompanied with ventriculitis has been reported in neonates and infants, but not in adults. In addition, this is the first case with erythromycin-induced hearing loss in the Japanese literature. Hearing should be regularly examined in patients who are treated with high-dose erythromycin >> or = 4 g/day), and the drug should be immediately discontinued when the patient develops hearing loss.