Background：Management of isolated mesenteric injury is affected by the presence of bowel injury. This study will assess the necessity of laparotomy for mesenteric injury. Methods：We examined retrospectively trauma with mesenteric injury for 11-years at a trauma center. Thirty-seven patients diagnosed as isolated mesenteric injury at the time of admission without intraluminal air on CT were examined retrospectively. Result：Blunt trauma was 37 cases. Laparotomy was performed in 32 cases, and bowel injury was complicated in 17 cases （45.9%）. Comparison between isolated mesenteric injury cases and complicated bowel injury cases, there were no significant difference. In laparotomy case, 7 cases （46.6%） needed bowel resection due to ischemia. Eight cases were changed laparotomy after initial non-operative management, and 5 cases had bowel injury. Conclusion：Although CT scan is useful for diagnosing mesenteric injury, it is difficult to rule out bowel injury. The rate of surgical repair for mesenteric injury is high, laparotomy should be performed.