A 15-year-old boy presented with intestinal obstruction two weeks following a blunt abdominal trauma. He had progressive bilious vomiting without abdominal distension or peritonitis. The contrast computed tomography (CT) scan of the abdomen provided the definitive diagnosis: there was an obstructing duodenal hematoma, which might have been slowly progressing or have arisen from secondary hemorrhage after the initial injury. The boy remained stable over a ten-day period of conservative treatment, and his obstructive symptoms and signs were resolved completely. A follow-up CT scan of the abdomen (16 days after admission) showed an almost complete resolution of the hematoma. Delayed duodenal hematoma causing intestinal obstruction has been reported rarely in previous literature. Occasionally a significant secondary hemorrhage resulting in intestinal obstruction can become life threatening. Clinical follow-up is paramount after initial recovery. Although conservative treatment suffices in most cases, the surgeon should be wary of the need for definitive surgical intervention if there is evidence of ongoing acute hemorrhage or of the obstructing hematoma failing to resolve. Laparoscopic drainage of the hematoma provides optimistic results for patients failing conservative management.