A 47-year-old man was complaining of consciousness disorder. He had acute kidney injury, hypokalemia, and severe metabolic alkalosis. Initial treatment using intravenous infusion of 0.9% saline and potassium chloride improved his consciousness. It was clarified that he was a severe alcohol abuser who habitually selfvomited. We diagnosed him with volume depletion and pseudo-Bartter's syndrome due to loss of chloride by habitual vomiting. Gastrointestinal endoscopy demonstrated pyloric stenosis, which was ameliorated by Helicobacter pylori eradication therapy. We should consider volume depletion and pseudo-Bartter's syndrome as differential diagnoses when we encounter patients with acute kidney injury and severe metabolic alkalosis.