We describe a case of meningeal carcinomatosis of the internal auditory meatus presenting as sudden deafness accompanied by dizziness. A 54-year-old woman complained of acute right-side hearing loss in October 2014. The pure tone audiometry test revealed right-side hearing loss of 47.5 dB. She was treated with oral steroids. Her hearing as well as her symptoms of dizziness worsened and she was admitted for further examination. Her right and left-side hearing had worsened to 105.0 dB and 47.5 dB, respectively. A magnetic resonance imaging scan of the head revealed bilateral enhancement of the internal auditory canal and multiple brain metastases. The chest radiograph revealed a mass in the left lung. Adenocarcinoma of the lung was diagnosed. Lumbar puncture yielded no evidence of carcinoma cells in the cerebrospinal fluid, but an increased number of lymphocytes was confirmed. A diagnosis of multiple brain metastases and leptomeningeal metastasis from the adenocarcinoma of the lung was considered. Whole-brain radiation therapy (30 Gr/10 fractions) was administered. Progressive bilateral hearing loss is a rare first manifestation of meningeal carcinomatosis. It is quite important to consider the possibility of this condition when patients present with sudden deafness.