In recent years researchers have gained a greater understanding of the immunological and inflammatory mechanisms underlying rheumatoid arthritis. Much of their efforts have centred on the role of the cytokine network in the pathophysiology of the disease. On the basis of these discoveries pharmaceutical companies have developed several potential biologic agents aimed at addressing cytokine imbalance and its subsequent effects on cartilage damage and joint destruction in rheumatoid arthritis. This pocketbook will provide an overview of the role of cytokines in the disease process, with a particular focus on one cytokine, interleukin-1 (IL-1) and on the therapeutic efficacy of its inhibition.