Trisomy 8 in myelodysplastic syndrome (MDS) plays an important role in concurrent intestinal Beh?et's disease (BD) pathogenesis.Here,we reported a case of intestinal BD combined with MDS involving trisomy 8.A 48-year-old woman who has had a 20-year history of recurrent oral ulcer,perineal ulcer and iris,was diagnosed as MDS with trisomy 8 four years ago.She developed high fever and acute abdominal pain.Multiple ulcerative perforations in ileum and colon were found by endoscopy,meeting the criteria for intestinal BD.The patient was successfully treated with immunomodulatory drugs.