Rheumatoid arthritis (RA) is a common disease that affects up to 1% of the population, and causes significant morbidity and early mortality. The aetiology of RA is unknown; however, in the last 10 to 15 years significant advances in molecular technology have provided a greater understanding of the pathogenesis of the disease. This has led to the development of new approaches to the treatment of RA. The disease modifying antirheumatic oral agent leflunomide inhibits the proliferation of activated T cells that are important in the inflammation and degradation of synovial tissues. The 2 biological agents approved for the treatment of RA, infliximab and etanercept, are inhibitors of the pro-inflammatory cytokine, tumour necrosis factor-alpha (TNFalpha). Infliximab is a chimeric human/mouse monoclonal antibody which is administered by intravenous infusion and binds with high affinity to TNFalpha, thereby neutralising its effects. Etanercept is a recombinant, soluble TNF receptor molecule which is administered subcutaneously and binds to TNFalpha in the serum rendering it biologically inactive. The protein A immunoadsorption column is a medical device that in conjunction with plasmapheresis can be used in patients with refractory RA. These agents have provided new and effective therapies for the treatment of patients with RA.