This single arm study will assess the safety of MabThera plus methotrexate in patients with rheumatoid arthritis who have had a lack of response to 1-5 DMARDs or biological agents. Patients will receive MabThera (1g i.v.) on days 1 and 15, concomitantly with methotrexate >=15mg p.o./week. The anticipated time on study treatment is 3-12 months, and the target sample size is 100-500 individuals.