Abdominal CTs of 57 patients with bowel perforation after blunt abdominal trauma were retrospectively analyzed to determine: the diagnostic accuracy of the perforation site, and the differential findings according to the elapsed time from the trauma. Diagnostic accuracy of the perforation site was as follows: duodenum (100%), jejunum (81%), jejunoileal junction (100%), ileum (93%), and colon (20%). Extraluminal air was the only significant differential findings according to the elapsed time, and was seen more commonly on late stage of bowel perforation (P<.05).