OBJECTIVE To describe the long-term outcome of juvenile idiopathic arthritis (JIA). METHODS All patients with JIA referred to a pediatric rheumatology center between 1978 and 1988 were identified and invited to undergo an assessment. Patients with JIA from a population-based cohort from East Berlin were included. The outcome assessment considered changes in body function and structure (e.g., mortality, joint abnormalities, disease activity), activities at the individual level (Health Assessment Questionnaire), and participation in society (e.g., mobility, educational and vocational background). RESULTS Of 260 eligible patients, 215 (83%) were evaluated. Subtypes of JIA at disease onset included oligoarthritis (40%), polyarthritis (14%), systemic arthritis (14%), psoriatic arthritis (1%), enthesitis-related arthritis (15%), and other arthritis (16%). Followup was conducted after a median of 16.5 years. No deaths occurred in this cohort. At followup, approximately half of the patients had active disease and/or changes in body structures to a variable extent. Approximately one-third of patients rated themselves as being functionally limited. Patients demonstrated good social integration: few mobility problems were reported, and the educational achievements of patients were higher and their rate of unemployment was lower compared with the age-matched population. No significant differences in outcome were found between the population-based and the referral-based cohorts. CONCLUSIONS Even though approximately half of the JIA patients had more or less distinctive changes in body function and/or structure after a disease duration of >15 years, fewer than 10% were severely disabled or handicapped. Because JIA often persists into adulthood, long-term followup and care are necessary.