Two cases of postoperative intussusception (POI) are reported. Both children, 13 and 6 months old, had long and difficult surgery for abdominal neuroblastoma after four courses of chemotherapy. Obstruction of the small intestine occurred on the fifth postoperative day, after feeding had been started again, in the first child, and on the third day in the second one. Surgery revealed a loose ileo-ileal invagination of 10 and 15 cm respectively, which was easily reduced. The postoperative course was uneventful in both cases. Although POI is a classical complication of abdominal surgery, it is often forgotten. In the cases described, the first surgical procedure combined most causative factors for POI: young age, preoperative chemotherapy, prolonged general anaesthesia, extensive retroperitoneal dissection close to components of the neurovegetative system. The use of opioids for postoperative analgesia may be an additional risk factor, as they alter intestinal motility. Epidural analgesia with local anaesthetics should be preferred in such cases.