Nine cases of duodenal fistula complicating Crohn's disease are reported. All nine patients were male. Four patients had Crohn's disease of the ileum and five had ileocolitis. No patient had primary duodenal Crohn's disease. Because attempt at primary closure of the duodenal defect may fail, our treatment of choice has been formal cross cut two-layered duodenojejunal anastomostis with extensive drainage of the area postoperatively. This treatment has been associated with no mortality and little morbidity, and no late recurrence of duodenal fistula.