The introduction of MRI in spondyloarthritis (SpA) constitutes a major advance and is increasingly being implemented in clinical practice in cases in which clinical suspicion of SpA is high yet pelvic radiography is equivocal. Recent studies and development of consensus by international experts support the routine use of specific MRI sequences and scanning protocols for the evaluation of the sacroiliac joints in diagnostic work-up. There is also agreement that the finding of bone marrow edema in the sacroiliac joints carries a high probability of SpA, and emerging data indicate that the finding of erosion may also be diagnostically helpful, even in preradiographic SpA. Recent studies suggest that the diagnostic role of MRI may be further enhanced through the study of additional MRI sequences and prospective studies using systematic methodologies aimed at further scrutiny of structural lesions and the contribution of spinal imaging. Interest in MRI for SpA is poised for substantial growth.