Duodenal fistulas in patients with Crohn's disease are rare, and up to one hundred cases were described in the medical literature. We report an additional case of a 40-year-old male who underwent an ileo-ascending colectomy 13 years ago for Crohn's disease and was admitted to our unit with palpable abdominal mass and persistent cutaneous fistula. Preoperative fistulography and barium enema demonstrated Crohn's disease recurrence in the site of the ileocolonic anastomosis and external fistula communicating with the pre-anastomotic ileum. At surgery, Crohn's disease recurrence in the site of ileocolonic anastomosis with ileo-cutaneous fistula was confirmed and an additional ileo-duodenal fistula was detected incidentally. The patient underwent resection of the affected bowel and simple closure of the duodenal fistula with omental pedicle graft transposition between the duodenum and the ileocolonic anastomosis. Postoperative period was uneventful. We review the literature and discuss the incidence and treatment strategy of duodenal fistulas complicating recurrent Crohn's disease in the site of the ileocolonic anastomosis. The authors highlight that simple closure of the duodenal defects is appropriate only for small duodenal fistulas and omental transposition between ileo-colonic anastomosis and duodenum during the primary and repeated resection should be considered as an effective prevention method of duodenal fistulas formation.