A 59-year-old woman with rheumatoid arthritis was treated quite successfully with infliximab, but her serum aminotransferase levels were markedly elevated; this was diagnosed as acute exacerbation of hepatitis B and she was treated with lamivudine, and infliximab was discontinued. The rheumatoid arthritis disease activity was uncontrollable after the discontinuation of infliximab, and we therefore initiated tocilizumab treatment (after obtaining the patient's informed consent) together with lamivudine prophylaxis. After tocilizumab administration her rheumatoid arthritis disease activity was significantly attenuated, and the activity has remained low, without re-exacerbation of the hepatitis, for more than 2 years since the initiation of the tocilizumab.