The aim of this study was to identify the prevalence of functional disability and the possible factors that may be associated with functional disability in children and adolescents with juvenile idiopathic arthritis (JIA) in Sharkia Governorate. Methods: This cross sectional study was carried out in Rheumatology and Rehabilitation department, Faculty of Medicine, Zagazig University Hospitals. Forty-eight consecutive patients of JIA aged from 7 to 17 years underwent assessment of socio-economic and demographic characteristics, functional ability using the childhood health assessment questionnaire (CHAQ), disease activity using the Juvenile Arthritis Disease Activity Score based on 27 joints (JADAS27), psychological symptoms using the Children’s Depression Inventory (CDI) score. Results: Multivariate modeling was applied to determine the factors that associated with functional disability. A total of 80 % of the patients (39 of 48) had functional disability. In multiple regression analyses, high CDI scores (OR 20.78, 95 % CI 1.64 to 262.91, P =.019), JADAS-27 (OR 17.49% CI 2.16 to 141.62, P =.007), low socioeconomic status (OR 10.43, 95 % CI 1.24 to 87.57, P =.031) were strong predictors of functional disability in JIA patients. Conclusion: Our study on patients with JIA provides evidence suggesting that a total of 80 % of the patients had functional disability, that is associated with higher CDI scores, higher JADAS -27 and a low socioeconomic status.