We report the case of a 17 year old male patient, hospitalized for the evaluation of bleeding diarrhea with glairs. Colonoscopy and colonic biopsies allowed the diagnosis of ulcerative colitis (UC) in pancolitis. The patient put under corticosteroid and azathioprine. The evolution was marked by the disappearance of bleeding diarrhea. Faced with persistent iron deficiency anemia despite clinical remission, which worsened during the evolution and absence of geophagia or a capital deficiency, a gastroscopy was performed, the upper gastrointestinal endoscopy has not objectified visible macroscopic anomaly, however pathological study of duodenal biopsies showed partial villous atrophy with intraepithelial lymphocytoce. After the suspicion of a celiac disease, the assessment was completed by an immunological study that showed anti-gliadin antibodies and endomysial antibodies. The patient was put under gluten-free diet associated with the maintenance treatment of ulcerative colitis. On the occasion of this observation, we emphasize the rarity of this association and we the complex pathogenesis of celiac disease that could have similarities with that of ulcerative colitis.