Myelodysplastic syndromes (MDS) with trisomy 8 (+8-MDS) associated with inflammatory and autoimmune diseases (IADs) (n=21) were compared with 103 cases without IADs. The IADs were mostly Behçet’s-like disease in 11 (52%) patients or inflammatory arthritis in 4 (19%). Overall 90% (15/17) of patients received steroids, with complete and partial response in 7/17 (35%) and 8/17 (47%) respectively. For 7 patients receiving azacytidine, five achieved remission and two partial response regarding IADs. As compared with the 103 cases without IADs, those with IADs were more often non-European (p = 0.005) and had poor karyotype (p < 0.001). We found no difference in overall survival or acute myeloid leukemia progression between two groups. We compared the 11 cases of +8-MDS associated with Behcet’s-like syndrome and those from litterature (n = 28) with Behcet’s disease and Crohn’s disease. By comparison with 63 Behcet’s disease those with Behcet’s-like syndrome and +8-MDS were older (median 75 vs 48 years; p=0.0003) and had less pseudofolliculitis (11% vs 62%; p=0.0045) and ocular impairment (0% vs 52%; p=0.0008), but more frequent gastrointestinal involvement (60% vs 13%; p=0.0005). By comparison with 100 Crohn’s disease, our were older (median 72 [53–78] vs 36 [27–45] years; p=0.0002) and more frequently had oral aphtosis (97% vs 5%, p