To determine the potential aetiological factors of small bowel perforation in the premature neonate, we performed a retrospective chart review of those neonates with spontaneous intestinal perforation (SIP) of the small bowel seen in our tertiary paediatric hospital between January 1980 and December 2000. Data were collected on gestational feto-maternal health, medical interventions prior to perforation and the subsequent operative and laboratory findings. There were 23 patients with SIP of the small bowel over the 21-year review; 65% were male. There were 7 twin pregnancies but no cases linked to maternal drug abuse. The median gestational age was 27 weeks, the median birth weight 973 g, 19 neonates required ventilation, 15 steroids and 13 indomethacin. The median age at diagnosis was 7 days, heralded by rapid development of abdominal distension in 22 patients. Surgical intervention in addition to insertion of a peritoneal drain was required in 19 patients. Positive microbiological cultures of blood or peritoneal fluid at operation were documented in 8 patients; 5 grew Staphylococcus epidermidis and 4 Candida species. Perforations were located in the ileum in 20 and the jejunum in 1. Deficiency of the muscularis propria was found in 6 patients. Of the 6 deaths, 2 neonates had significant co-morbidity in addition to extreme prematurity. Small bowel SIP occurs in the premature neonate after the first week of life and usually presents with abdominal distension. Putative risk factors identified included twin gestation, neonatal ventilation, use of steroids and indomethacin, infection with Staphylococcus epidermidis and Candida species and deficiency of enteric smooth muscle.