Background: Juvenile Idiopathic Arthritis (JIA) is one of the most prevalent pediatric rheumatic disorders causing severe impairments such as persistent pain, impaired physical function and subsequent sleep disturbance that may increase the risk of an overall sedentary lifestyle. Aim of this study was to identify the relationship between sleep quality, functional ability and lifestyle habits of children with juvenile idiopathic arthritis. Design: A descriptive correlational design was utilized. Setting: The study was took place at the outpatient clinic of the rheumatology and rehabilitation department at Zagazig University Hospitals. Subjects: Purposive sample of fifty-five children with JIA aged 6–16 years were included from the previous mentioned setting. Tools: Four tools were used to gather the required data. Tool I: Children bio socio demographic characteristics. Tool II: Sleep quality scale (SQS). Tool III: Functional ability questionnaire. Tool IV: Lifestyle questionnaire. Results: It was clarified that more than one third of children had poor sleep quality and two fifths of them had low functional ability, as well as more than two fifths of them had poor lifestyle habits. Conclusion: Juvenile idiopathic arthritis had a negative effect on sleep quality, functional ability and lifestyle habits of the studied children. Moreover, there was highly statistically significant positive correlation between children's sleep quality, functional ability and their lifestyle habits. Recommendations: Developing an educational program regarding lifestyle modifications is mandatory for children with JIA.