Abstract: Introduction: The association of Behcet’s disease (BD) and Ankylosing Spondylitis (AS) is still a controversial subject. As the presence of sacroiliac joint (SIJ) involvement is an essential criterion in the diagnosis of AS, we decided to determine the prevalence of SIJ involvement in BD and compare it with control group. Materials & Methods: We selected randomly 199 BD patients and 168 non-BD cases (CG), in a 12 month period (between April ...