Objective. To assess the effects of regular aerobic training combined with range of motion (ROM) exercises on aerobic capacity, quality of life, and function in children with juvenile idiopathic arthritis (JIA). Methods. Thirty patients with JIA and 20 healthy age- matched controls (mean age +/- SD, 11.3 +/- 2.4 versus 11.0 +/- 2.3, resp.;.. > 0.05) were included. All patients performed aerobic walking (4 days a week for 8 weeks) and active and passive ROMexercises of involved joints. All patients completed the childhood health assessment questionnaire (CHAQ) and the child health questionnaire. ROM measurements of joints were performed by using universal goniometer. Aerobic capacity was determined by measuring peak oxygen uptake (VO2peak) during an incremental treadmill test. Results. Peak oxygen uptake and exercise duration were significantly lower in JIA group than in controls (32.5 +/- 6.6 versus 35.9 +/- 5.8 and 13.9 +/- 1.9 versus 15.0 +/- 2.0, resp.; < 0.05 for both). Eight- week combined exercise program significantly improved exercise parameters of JIA patients (baseline versus postexercise VO2peak and exercise duration, 32.5 +/- 6.6 to 35.3 +/- 7.9 and 13.9 +/- 1.9 to 16.3 +/- 2.2, resp.;.. < 0.001 for both). Exercise intervention significantly improved CHAQ scores in JIA patients (0.77 +/- 0.61 to 0.20 +/- 0.28, P < 0.001). Conclusion. We suggest that regular aerobic exercise combined with ROM exercises may be an important part of treatment in patients with JIA.