Over a 14-year period 587 children under 13 years of age were admitted with blunt injury to the abdomen. Twenty-nine (4.9 per cent) of these were found to have bowel rupture. Evidence of peritonitis was present at initial evaluation in 11 children (38 per cent). Radiological evidence of perforation (pneumoperitoneum) was present in only five of 27 (19 per cent) with a further six of 27 (22 per cent) showing dilated loops of bowel or fluid levels. Thus 59 per cent of radiographs were not diagnostic. The mean time from admission to laparotomy was 17 h. Proximal bowel perforation was common and perforation at multiple sites occurred in five patients; 59 per cent had a concomitant injury which resulted in two deaths (from head injury). Initial clinical and radiological evidence of bowel perforation can be misleading and reliance on such indicators may result in significant diagnostic delay. Frequently repeated clinical examination is advocated; progression of abdominal signs should alert the clinician to proceed to laparotomy.