The use of methotrexate in rheumatoid arthritis is reviewed. Methotrexate, a folic acid antagonist, is sometimes employed in an attempt to symptomatically control patients whose disease does not respond adequately to conventional therapies. Systemic administration of 7.5-15 mg/wk in a "pulse" fashion appears to be effective without precipitating severe adverse effects. However, concern over potentially serious side effects and a lack of well-controlled clinical trials have limited its use to severe, refractory disease. Further studies are needed before its role in rheumatoid arthritis can justifiably be expanded.