A 61-year-old man was admitted to our institution with progressive hypoacusia, double vision, and lightheadedness. Neurological examination on day 6 of his illness showed severe hypoacusia, mild confusion, ocular motility disorder, truncal ataxia and absence of a deep tendon reflex. MRI fluid-attenuated inversion recovery imaging revealed symmetrical high intensities in the tectum of the midbrain, involving the bilateral inferior colliculi and the bilateral medial thalami, which suggested Wernicke encephalopathy (WE). Thiamine was administered immediately after completion of the MRI, and the patients' hearing and other abnormal neurologic signs improved rapidly within a few days, except for the absence of the deep tendon reflex. Whole blood examination at admission revealed very low levels of vitamin B1. The patient was discharged on day 19, and MRI on day 39 showed the disappearance of the abnormal high intensities involving the bilateral inferior colliculi. The present case indicates that hypoacusia and abnormal MRI signal due to WE might be normalized by administration of thiamine a few days after the onset of symptoms.