A 27-year-old man was admitted to the hospital because of central abdominal pain. There was rebound tenderness around the umbilical region. Abdominal simple X-ray film demonstrated intestinal obstruction and abdominal CT showed thicking of the wall of the small intestine. The patient underwent an emergency laparotomy with a diagnosis of panperitonitis. Laparotomy showed a Meckel's diverticulurn at the ileum 40cm from the terminal ileum. Small bowell was obstructed at the diverticulum because of fibrous adhesion. The ileum was perforated at the oral side of the diverticulum. A partial resection of the small intestine was performed. Histopathological examination confirmed the diagnosis of Meckel's diverticulum with ectopic gastric mucosa and perforated ulcer. Meckel's diverticulum with perforated ulcer is rare, and so we report the case together with presenting some bibliographical comments.