The results of the retrospective study evaluating efficacy and safety of tocilizumab treatment in 75 patients with severe systemic-onset juvenile idiopathic arthritis refractory to standard immunosuppressive therapy are presented in the paper. Inactive disease was documented in 64% of patients after 6 months of treatment and in 73% of patients after 12 months. Adverse events manifested as mild and moderate infections as well as laboratory abnormalities: leukopenia, neutropenia, and elevated aminotransferase levels.