OBJECTIVE To describe a cohort of Finnish juvenile idiopathic arthritis (JIA) patients, to recognize those young adults who are at risk of becoming socially restricted by their long-term rheumatic disease, and to assess which areas of self-rated health-related quality of life (HRQoL) are associated with the emergence of restricted social participation. METHODS A total of 195 young adults with JIA completed questionnaires addressing demographics, health behaviour, physical activity, functional ability, HRQoL, depressive symptoms, and self-esteem. Patients were classified as having non-restricted social participation if they were engaged in studying, working, maternity leave, or military service, and restricted social participation if they were unemployed or on disability pension. RESULTS Of the patients, 162 (83%) were considered as having non-restricted social participation and 33 (16%) restricted social participation. Among patients with restricted social participation, five (15%) were on disability pension and 28 (85%) were unemployed. Patients with restricted social participation participated less in leisure-time non-physical activities (p = 0.033), felt more disturbed during their leisure time (p = 0.010), had lower self-esteem (p = 0.005), and had higher disability scores (p = 0.024). HRQoL scores revealed statistically significant differences between the groups: physical functioning (p = 0.043), social functioning (p = 0.016), and emotional well-being (p = 0.049) were all lower in patients with restricted social participation. CONCLUSIONS Socially restricted patients showed a higher degree of disability, and lower levels of physical functioning, self-esteem, emotional well-being, and social functioning. These patients should be recognized earlier and interventions provided to enhance their social participation.