This observational, prospective, multicenter study will evaluate the efficacy and safety of MabThera/Rituxan in participants with active rheumatoid arthritis and an inadequate response or intolerance to one anti-TNF therapy. Participants who receive MabThera/Rituxan according to the current standard and in line with the summary of product characteristics at a dose of 1000 milligram (mg) intravenously on Days 1 and 15 will be followed for 20 weeks.