The treatment of chronic arthritic diseases has undergone some dramatic changes over the past few years. In particular, a new class of drugs called the tumor necrosis factor-alpha antagonists has transformed the management of rheumatoid arthritis, and decision makers are now consid1ering their use in psoriatic arthritis and ankylosing spondylitis. Whilst short-term clinical trials suggest that tumor necrosis factor-alpha antagonists improve physical function and pain linked to disease activity, this class of drug has generated controversy owing to its substantial cost. Pharmacoeconomic studies conclude that tumor necrosis factor-alpha antagonists result in significant increases in health-related quality of life; however, the cost-effectiveness of this class of drug remains uncertain, particularly in the treatment of psoriatic arthritis and ankylosing spondylitis. This paper reviews pharmacoeconomic analyses examining the cost-effectiveness of tumor necrosis factor-alpha inhibitors in rheumatoid arthritis, psoriatic arthritis or ankylosing spondylitis.