A 6-year-old boy presented with abdominal pain and vomiting after a history of blunt abdominal trauma. Ultrasounds showed biliary sludge initially leading to a diagnosis of acute cholecystitis, but the patient did not improve with medical treatment. Repeated ultrasound then revealed an epigastric mass. A CT scan confirmed a duodenal hematoma from the trauma. The boy underwent surgery where the duodenal injury was repaired. Duodenal injuries from blunt trauma can be difficult to diagnose but require suspicion and exploration if certain intra-operative findings are present.