Rheumatoid arthritis is a common debilitating disease. Chronic joint inflammation leads to irreversible joint damage. Disability is a common sequel, therefore it is a major healthcare burden. Treatment by convention disease modifying anti-rheumatic drugs improves symptoms and signs but does not improve long-term prognosis. Tumour necrosis factor alpha is a powerful pro-inflammatory cytokine. Blocking this cytokine by either monoclonal antibody or soluble receptor reduces inflammation, improves symptoms and significantly reduces joint damage. Tumour necrosis factor alpha antagonists are major breakthroughs in the treatment of rheumatoid arthritis. In the UK, they are approved for the treatment of rheumatoid arthritis in patients with active disease who have failed at least two disease modifying anti-rheumatic drugs.