This observational study will evaluate the safety, tolerability and efficacy of RoActemra/Actemra (tocilizumab) in combination with methotrexate in patients with moderate to severe rheumatoid arthritis. Data will be collected for 12 months from patients initiated on treatment with RoActemra/Actemra (8 mg/kg intravenously every 4 weeks) and methotrexate (weekly dose at the discretion of the physician).

Inclusion Criteria:

• Adult patients, >/= 18 years of age
• Moderate to severe rheumatoid arthritis
• RoActemra/Actemra treatment initiated by rheumatologist in an Arthritis Center for (up to 2 months prior to study entry)

Exclusion Criteria:

• History of severe allergic or anaphylactic reactions or known hypersensitivity to any component of the drug
• Active, severe infection or history of recurrent clinically significant infection
• Pregnancy
• Treatment with an investigational agent within 4 weeks (or 5 half-lives of the investigational agent, whichever is longer) before baseline visit
• Methotrexate intolerance

Patients with moderate to severe rheumatoid arthritis initiated on treatment with RoActemra/Actemra in combination with methotrexate