Wernicke's encephalopathy is an acute neurological syndrome resulting from thiamine (vitamin B1) deficiency. Early recognition is important because timely thiamine supplementation can reverse the clinical features of the disease. The aim of this article is to provide an update on the typical and atypical neuroimaging findings of the acute phase of the disease. Wernicke's encephalopathy is characterized by a quite distinct pattern of MR alterations, which include symmetrical alterations in the thalami, mamillary bodies, tectal plate, and periaqueductal area, but atypical alterations may also been seen. A thorough knowledge of the neuroimaging findings of Wernicke's encephalopathy will assist in arriving at an early diagnosis, thus reducing the morbidity and mortality associated with this disease.