A young woman presented with severe acute abdominal pain, superimposed on a past history of similar attacks. Ultrasonography revealed a small bowel intussusception. This was confirmed on laparotomy, and the lead lesion, an ileal polyp, was excised. Histology showed this to be a Peutz-Jeghers hamartoma. The possibility of intussusception should be kept in mind in adults presenting with acute abdominal pain. Ultrasonography can provide rapid and accurate corroboration.