We report a 55 year old Japanese man with a history of alcohol abuse, who was in a near fasting state for the previous few days.He was admitted to our hospital with abrupt disturbance of consciousness. He presented disturbance of consciousness with extreme hypoglycemia and ketoacidosis with high β-hydroxybutyric acid concentration. Taking into account his living history, we diagnosed with alcoholic ketoacidosis (AKA). Symptoms ameliorated with glucose injection and fluid loading. AKA patients show abdominal pain, nausea or vomiting, but they are usually alert and lucid despite the severe acidosis. This case, however, presented comatose status caused by hypoglycemia. Poor oral intake of this patient was assumed to be the cause of hypoglycemia. Alcoholism may cause hypoglycemia accompanying with AKA, due to a low carbohydrate intake, the inhibition of gluconeogenesis, and reduced hepaticglycogen storage as seen in this case. Here, we report a case of AKA that demonstrated hypoglycemia with the literature review.