Juvenile idiopathic arthritis (JIA) is the most common rheumatic disease in childhood, resulting in short- and long-term disability. It includes a heterogeneous group of diseases, of which systemic JIA is often resistant to treatment. IL-6 plays a significant role in systemic JIA since it is elevated in serum and correlates with disease activity, including joint involvement, acute phase reactants and fever. Blocking the IL-6-induced signal could therefore be an attractive treatment approach. The use of tocilizumab, a humanized anti-IL-6 receptor antibody, for the treatment of systemic JIA is described. The purpose has been to review the controlled clinical trials evaluating the efficacy and safety of tocilizumab for the treatment of systemic JIA. In two Phase III randomized, double-blind controlled studies a rapid and high response rate has been achieved both regarding systemic features and arthritis activity together with a tolerable safety profile in children with systemic JIA refractory to conventional treatment.