Rationale: etanercept inhibits the effects of tumor necrosis factor, which plays an important role in the progression of rheumatoid arthritis. A study of children with polyarticular course juvenile rheumatoid arthritis showed that Enbrel had efficacy and was generally well tolerated in children ages 4-17 who had moderately to severely active disease and who failed treatment with one or more disease modifying antiarthritic drugs. The children in the study may have had arthritis onset of pauciarticular, polyarticular, or systemic nature. Systemic onset juvenile rheumatoid arthritis (SOJRA) may result in approximately one-third of patients having significant long-term disability. Purpose: the Phase 4 study is designed to further define the safety and efficacy of etanercept in those children with SOJRA.