Thiamine is a water-soluble vitamin that plays a role in the metabolism of glucose. Thiamine deficiency affects cardiovascular and nervous systems. Wernicke encephalopathy is characterized by oculomotor abnormalities, ataxia and cognitive deterioration caused by thiamine deficiency. It is most commonly observed in chronic alcoholics. It may also occur in patients who receive long-term total parenteral nutrition. In this study, we present the case of a 50-year-old male patient who underwent surgery for laryngeal cancer, who stayed in the intensive care unit for a prolonged period and received total parenteral nutrition because of the inability of oral intake.