The aim of this non-interventional, prospective, observational study is to assess the effectiveness and tolerability of RoActemra (tocilizumab) used as a first-line biologic treatment in participants with moderate to severe active RA who are inadequate responders to disease-modifying antirheumatic drugs (DMARDs), or participants who are intolerant to DMARDs, in a routine clinical practice setting in Poland. The length of the entire study will be 24 months.