Most data concerning the role of cytokines in chronic arthritides have been obtained in adult rheumatoid arthritis. In this paper we review the available evidence regarding the role of the inflammatory cytokines interleukin-1, interleukin-6, and tumor necrosis factor in juvenile rheumatoid arthritis, focusing in particular on the differences among the various onset types. Results from the analysis of cytokine expression may provide the basis for the use of specific anticytokine treatment. Recent clinical trials in adult rheumatoid arthritis have demonstrated the feasibility and clinical usefulness of these treatments.