Tocilizumab, a humanized monoclonal antibody against the interleukin-6 receptor, is therapeutically effective in patients diagnosed with rheumatoid arthritis (RA) compared with placebo. However patients treated with tocilizumab are at increased risk of several adverse effects including anaphylaxis and serious infections that may lead to hospitalization or death. Therefore, the risks and benefits of treatment with tocilizumab should be considered carefully and close monitoring of patients for development of signs and symptoms of side effects is required during and after treatment. Here, we report on a rare case of anaphylaxis and severe sepsis caused by cellulitis in a patient with RA after tocilizumab treatment. (J Rheum Dis 2016;23:55-60)