The authors report what they believe is the first report in the English literature of acute inflammation of ectopic pancreatic tissue in a Meckel's diverticulum. A 29-year-old man presented with acute abdominal pain and a clinical diagnosis of acute appendicitis was made. Laparotomy revealed a normal appendix and a Meckel's diverticulum with gross inflammation at the distal end. Microscopic examination showed acute inflammation limited to ectopic pancreatic tissue in the wall of the diverticulum. Fat necrosis was present. The possible pathophysiologic mechanisms are discussed.