Ankylosing spondylitis (AS) is a chronic inflammatory disorder of the spine that can lead to significant disability if left untreated. Although conventional treatments can be successful in alleviating symptoms, they have not been shown to stop progression of the disease. The proinflammatory cytokine tumor necrosis factor (TNF) is central to the pathogenesis of AS. Several TNF-α blocker drugs such as infliximab, adalimumab, etanercept and golimumab have been developed and shown to control symptoms effectively, possibly preventing both clinical and radiographic progression of the disease in patients with AS. Acute inflammatory lesions in the spine and sacroiliac joints can be effectively suppressed by the TNF-α blockers in AS, suggesting that bone destruction and bone proliferation might be prevented.