OBJECTIVE To examine variability in health-related quality of life (HRQOL) in children with juvenile idiopathic arthritis (JIA) experiencing no or minimal clinical symptoms, and in a subgroup with polyarticular JIA treated with biologic agents for 12 months. METHODS We defined 3 samples using a database of patients ages 2-18 years with JIA (n = 524; patient visits [PV] = 2,354): visits (PV = 2,155) with no or minimal clinical symptoms on at least 1 of 4 measures (active joint count, pain, physician global disease rating, Childhood Health Assessment Questionnaire); visits (PV = 941) with no or minimal symptoms on all 4 measures; and children (n = 31) with polyarticular JIA treated with biologic agents for 12 months. HRQOL was measured using the Pediatric Quality of Life Inventory (PedsQL) and the percentage of patients with suboptimal HRQOL was determined. RESULTS In PV with a PedsQL score, suboptimal HRQOL by self-report occurred in 362 (20.6%) PV with at least 1 indicator of minimal symptoms, and in 64 (7.9%) PV with all 4 measures indicating minimal symptoms (519 [25.7%] and 95 [10.7%], respectively, by parent report). For children with polyarticular JIA treated for 12 months with biologic agents, 7 (25.9%) patients by self-report and 10 (35.7%) patients by parent report were in the suboptimal range of HRQOL. CONCLUSIONS A substantial percentage of patients with JIA who report no or mild clinical symptoms experience suboptimal HRQOL. This is also true for patients with polyarticular JIA treated with biologic agents for 12 months. Although disease activity and clinical symptoms are related to HRQOL, considerable unexplained variation in HRQOL exists. HRQOL needs to be assessed independently regardless of clinical status.