Over a 16-year period, 33 newborn infants developed necrotizing enterocolitis (NEC) following some form of operation (accounting for 19 per cent of all neonates with NEC), including repair of myelomeningocele, intestinal atresia, gastroschisis and congenital diaphragmatic hernia. The neonates with postoperative NEC had a median birth-weight of 3.05 (range 1.0-4.4) kg, and median gestational age of 40 (range 27-41) weeks. Twenty patients were treated non-operatively. The remaining 13 required operation for complications of NEC. Twenty-three patients are alive and have been followed for a median of 66 (range 3-168) months. If a neonate deteriorates following any operation NEC must be included in the differential diagnosis.