OBJECTIVE: To (1) estimate the health-related quality of life (HRQOL) of children with childhood-onset systemic lupus erythematosus (cSLE) and compare it to that of normative cohorts; (2) assess the relationship of HRQOL with cSLE disease activity and damage; and (3) determine the effects of changes of disease activity on HRQOL. METHODS: Patients with cSLE (n = 98) followed every 3 months completed HRQOL measures, the Pediatric Quality of Life Inventory Generic Core scale (PedsQL-GC), the Rheumatology Module (PedsQL-RM), and the Child Health Questionnaire (CHQ). The British Isles Lupus Activity Group Index (BILAG) was used to measure organ-system-specific disease activity. Physicians rated the course of cSLE between visits. RESULTS: At baseline, mean (standard deviation, SD) score [parent report] of the PedsQL-GC and the PedsQL-RM was 75 (17) and 79 (14), respectively; the mean (SD) of the CHQ physical summary score (CHQ-PHS) was 49 (7) and that of the CHQ psychological summary score was 42 (12). Higher BILAG scores, especially in the general, musculoskeletal, neurological, and vascular, but not the mucocutaneous, renal, cardiovascular, or hematological BILAG domains, were associated with a significantly lower HRQOL. Patients with damage had lower HRQOL than those without damage. All HRQOL measures included were at most modestly responsive to clinically important changes with cSLE. CONCLUSION: HRQOL with cSLE is significantly lower than that reported in healthy populations. Organ-specific involvement with cSLE has a differential effect on HRQOL. Higher disease activity and damage are associated with significantly lower HRQOL as measured by the PedsQL-RM and the CHQ-PHS, and worsening of cSLE leads to a further decline.