Abstract: Objective To study the reasons and possibly solutions for missed diagnosis of duodenal injury. Method The clinical records were retrospectively analyzed in 9 cases of missed diagnosis of duodenal injury treated in our hospital in the year 1992 to 2002. Results Of the 15 cases of duodenal injury, missed diagnoses occurred in 9 cases. The reasons for the missed diagnoses included complications by injuries of the other abdominal organs that concealed duodenal injuries, neglect of the light injuries, and the lack of clinical experience on the part of the young doctors. Conclusion Duodenal injury frequently occurs along with other abdominal organ injuries and is easy to escape detection, which can be avoided by careful preoperative examination of the characteristics of injuries and the patients’ clinical manifestations after the injury.