Juvenile Idiopathic Arthritis (JIA) is children's most common inflammatory rheumatic disease. The International League of Associations for Rheumatology (ILAR) defines it as a chronic arthritis condition that begins before the age of 16 lasts for six weeks or more, and has an unknown cause. Despite the gains made in the management of the disease of individuals with JIA with modern medical treatment methods, the physical and psychosocial problems caused by chronic inflammation negatively affect the daily living activities of individuals with JIA. On the other hand, in the JIA Core Set created by Outcome Measures in Rheumatology (OMERACT) in 2018, activities of daily living were included as a mandatory area that should be evaluated in all studies. Therefore, to ensure that individuals with JIA reach a state of complete well-being, multi-interdisciplinary health professionals are expected to address the activities of daily living, identify the factors that limit these activities, and create intervention plans for the factors to be determined. The literature shows that the daily living activities of patients with JIA are addressed with a limited number of subjective measurement tools. However, these methods have disadvantages due to their subjectivity. In this case, objective measurement methods are needed to quantify the physical performance of patients with JIA in terms of their daily living activities. The Glittre Activities of Daily Living Test, initially developed by selecting activities similar to daily living activities to evaluate functional capacity in pulmonary diseases, has the potential to address this gap. Since the activities in the test require using both the lower and upper extremities, it has the advantage of reflecting functional capacity and providing information about performance in daily life activities. Although it has potential, the Glittre Activities of Daily Living Test needs appropriate psychometric properties for clinical settings and research for JIA patients. To our knowledge, no studies have been conducted in the current literature on the validity and reliability of the Glittre Activities of Daily Living Test in JIA patients. Therefore, this study aimed to evaluate the test-retest reliability, construct validity, and minimum detectable change of the Glittre Activities of Daily Living Test in assessing activities of daily living in children and adolescents with JIA.