 This study will evaluate the safety and efficacy of MabThera in patients with active rheumatoid arthritis who have had an inadequate response or were intolerant to treatment with methotrexate. Eligible patients will receive MabThera 1000mg by intravenous infusion on days 1 and 15, and background methotrexate oral or subcutaneous dose of 10-25mg weekly. After the initial study period of 24 weeks, eligible patients may receive up to 3 re-treatments with MabThera. The anticipated time on study treatment is 1-2 years, and the target sample size is 100 individuals. 