An abdominal cocoon is an extremely rare condition, which has been mainly reported in young adolescent women as a cause of small bowel obstruction. In these patients the small bowel is encased in a fibrous sac called an abdominal cocoon. We herein describe a 74-year-old man who demonstrated an abdominal cocoon without having any history associated with an abdominal cocoon. A laparotomy showed bloody ascites and the entire small bowel was encased in a thin white fibrous membrane like a cocoon. The small intestine entered into a defect of the membrane, thus presenting as an internal hernia with intestinal necrosis. The necrotic intestine and the membrane were removed. A histopathological examination of the membrane showed a few signs of inflammation cells.