Background: Immune thrombocytopenia (ITP) is an acquired hematological disorder that is developed secondary to the production of auto-antibodies against platelets leading to isolated thrombocytopenia, in the absence of other causes of thrombocytopenia such as drugs, infections, malignancy, or other autoimmune diseases.Objective: This study aimed to determine serum levels of IL-17 and evaluate its prognostic significance in children with immune thrombocytopenia. Subjects and methods: A case control study carried out in Pediatric Hematology Outpatient Clinic, Zagazig University Hospitals during the period from September 2019 to August 2020. It included 100 subjects who were divided into 2 group; 50 children with ITP and 50 age and sex matched healthy children as a control group. Results: In this study, newly diagnosed patients with ITP had significantly higher levels of IL-17 compared to persistent and chronic patients with ITP (554.3, 259.9 and 158.6 pg/ml in in newly diagnosed ITP, persistent ITP and chronic ITP respectively, p<0.001). Conclusion:We concluded that serum IL-17 predicts susceptibility to ITP in Egyptian children with ITP.