Filtration leukocytapheresis (LCP) is a treatment for abnormal autoimmune states, which removes responsible leukocytes from the peripheral blood. To examine the efficacy of LCP therapy in the treatment of rheumatoid arthritis (RA), nine patients were selected, who were either resistant to methotrexate, or failed with methotrexate due to drug ineffectiveness or adverse side effects. For these patients, LCP therapy was performed once a week for five weeks. After five LCP treatments, the patients were observed for 12 weeks, to test the efficacy of the treatment. The definition of improvement given by the American College of Rheumatology (ACR core set) was used for efficacy evaluation of LCP therapy. As the result, 77.8% of the patients showed an ACR 20% response and 44.4% of the patients showed an ACR 50% response. With improvement of joint symptoms, IL-6 was significantly decreased at 8 weeks and 12 weeks after the treatment. The expression of adhesion molecules CD11a, CD11b, and CD18 on granulocytes decreased directly after the LCP treatment. No adverse side effect was monitored during the study period. These results indicates that LCP treatment is a useful treatment for RA patients who were resistant to methotrexate, or failed with methotrexate due to ineffectiveness or side effects of the drug.