Ankylosing spondylitis is the prototypical spondyloarthritis. Early diagnosis has gained clinical importance with the advent of new therapeutic options such as TNF-alpha inhibitors, which can dramatically improve clinical outcome when initiated early. Whole-body MRI can contribute important diagnostic information for detecting early forms of spondyloarthritis because it enables evaluation of all important joints that may be involved in the disease process as a one-stop shop modality. MRI allows much more accurate diagnostic evaluation of the thoracic spine, which is affected in the majority of patients. This article provides an overview of the use of whole-body magnetic resonance imaging (MRI) in the spondyloarthritides. The recommendations given reflect the most recent scientific data and expert opinions. The focus of this review is on MRI findings at both the axial and the appendicular skeleton and the technical feasibility of whole-body MRI in the clinical setting.