Acute necrotizing esophagitis, which presents as a black esophagus on endoscopy, is a rare disorder. We report a case of a 48-year-old male with acute necrotizing esophagitis, associated with alcoholic hepatitis. He was admitted to our hospital because of hematemesis. On initial upper esophagogastroduodenoscopy, diffuse friable black colored mucosa at whole length of the esophagus was observed. After conservative treatment with proton-pump inhibitor, esophageal mucosal lesion was healed without complication.