Until recently treatment options for AS were limited and based on non-steroidal anti-inflammatory drugs (NSAIDs), traditional disease modifying anti-rheumatic drugs (DMARDs) for the rheumatoid arthritis and physical therapy. The last decade witnessed a major advance in AS therapy with the use of anti-tumor necrosis factor (anti-TNF) agents. Anti-TNF agents have a substantial effect not only the axial disease but also in peripheral arthritis, enthesitis and extra-articular features (like psoriasis and inflammatory bowel disease). Currently there are four anti-TNF agents approved for AS: (1) infliximab which is a monoclonal chimeric antibody and given at a dose of 5 mg/kg every 6-8 weeks; (2) etanercept which is human TNF receptor fusion protein and administered subcutaneously at a dose of 50 mg/once a week; (3) adalimumab which is a humanized monoclonal antibody and administered as subcutaneous injection at a dose of 40 mg fortnightly; and (4) golimumab which is a fully human monoclonal antibody and administered subcutaneously at a dose of 50 mg once a month.