Background: Diaphragmatic hernias are relatively common after blunt and penetrating trauma. The difficulties in diagnosing traumatic diaphragmatic rupture (TDR) due to coexisting problems and the silent nature of these injuries at the time of first admission are the common causes of morbidity and mortality.

Materials and Methods: Medical records of 34 patients treated for post traumatic diaphragmatic hernias between August 2003 and June 2007 in Al-Zahra Hospital, were studied and data including age, sex, kind and site of trauma, timing and accompanying injuries were recorded and analyzed retrospectively.  

Results: There were 28 (82.4 %) men and 6 (17.6 %) women, with age range of 1 to 68 years and mean of 32.2±9.1. Rupture of diaphragm was left-sided in 22 (64.7%) and right-sided in 11 (32.4%) and both in 1 (2.9%). Blunt trauma accounted for 22 (64.7%) of patients. Elective operation was done in 7 (20.6%) cases. Diagnosis was established preoperatively in 15 patients (44.1%), and intraoperatively in 13 (38.2 %). The diagnosis was missed in 6 (17.7 %) patients in first operation. Strangulation of viscera was found in four patients. The longest interval between trauma and diagnosis was about 3 years in one case. Mean duration of hospital stay was 12.3 days. Multiple associated injuries were observed in 22 patients (66.7 %). Postoperative complications were encountered in 9 (26.5 %) patients, and the overall mortality was 14.7 %. 

Conclusion: Diaphragmatic hernia should be suspected in all kinds of trauma to thorax and abdomen, and the presence of such an injury should be excluded before terminating the exploratory procedures.