Infliximab is a chimeric monoclonal antibody capable of neutralizing human TNF alpha. A number of clinical trials for the treatment of rheumatoid arthritis(RA) with infliximab indicated that TNF alpha blockade was effective and well tolerated with the excellent results occurring at 3 and 10 mg/kg in combination with methotrexate. Treatment of RA patients with the combination of infliximab and methotrexate also prevented radiographic evidence of progression of joint damage. If the clinical efficacy is sustained and the safety is confirmed over the long term, infliximab may become an essential agent of choice for the treatment of RA.