A 21-month-old German shepherd crossbreed presented with a nine-month history of intermittent vomiting, anorexia and melaena interspersed with periods of clinical normality. Investigations suggested recurrent pancreatitis and the vomiting resolved with supportive therapy but recurred two weeks later. Abdominal radiographs revealed evidence of an intermittent abdominal mass which, on ultrasonography, had the typical appearance of an intussusception. At laparotomy, a gastroduodenal intussusception was found obstructing the pancreatic and bile duct outflows with perforation of the duodenal wall. The dog was euthanased. Postmortem examination and histology showed no obvious cause for the intussusception but confirmed pancreatic involvement. This is believed to be the first case of gastroduodenal intussusception reported in an animal.