Thirty-six patients with blunt duodenal injury have been treated at Detroit General Hospital since 1960. The majority of the patients were driving an automobile under the influence of alcohol and none were wearing seat restraints. Diagnosis was often delayed due to a failure to recognize the significant, but subtle, physical and roentgenographic findings of retro-peritoneal injury. Morbidity and mortality were related to a delay in operative intervention, the severity of duodenal injury, the presence and degree of associated pancreatic injury, and the choice of operative therapy. Patients with intramural hematoma or complete duodenal perforation without pancreatic injury did well with simple closure or evacuation of the hematoma. Patients with duodenal perforation and minor pancreatic injury did best after primary closure and pancreatic drainage if operation was performed within 24 hours; delay beyond 24 hours resulted in a high incidence of duodenal fistula after simple closure, and therefore is an indication for a bypass procedure, such as a distal gastrectomy, vagotomy, tube duodenostomy, and gastrojejunostomy. Patients with combined duodenal and major pancreatic disruption did best after a bypass procedure when the main pancreatic ductal system was intact, whereas pancreaticoduodenectomy was the best procedure when the main pancreatic duct was disrupted.