Edited by Drs. Juergen Braun and Joachim Sieper, this issue of Rheumatic Disease Clinics comprehensively reviews the state of the art of spondyloarthritis (SpA) diagnosis, prognosis, pathogenesis and genetic insights, and treatment. The worldwide burden of SpA now exceeds that of rheumatoid arthritis. General topics covered include inflammatory back pain, pathophysiology, imaging techniques, and therapeutic strategies.