Objective: Acute immune thrombocytopenic purpura (ITP) is a common acquired bleeding disorder. Intravenous immunoglobulin (IVIG) therapy is commonly given as initial treatment to pediatric patients with ITP. Factors that can predict the response to IVIG have not been fully determined. We retrospectively evaluated whether the clinical and laboratory findings of pediatric patients with ITP at the time of diagnosis could predict the response to IVIG and progression to chronic ITP. Methods: A total of 45 patients with newly diagnosed ITP who were initially treated with IVIG were evaluated between January 2016 and December 2019. Short-term response was estimated by platelet counts 2 weeks after IVIG, and long- term response was assessed by thrombocytopenia-free survival (TFS). TFS was defined as the probability of survival without treatment failure after initial IVIG, such as relapse, requiring additional therapeutic interventions, or progression to chronic ITP. Results: In univariate analysis, age ≥25 months (p=0.002), platelet count ≤6.9x109 /L (p=0.034), and hemoglobin (Hb) level >12.4 g/dl (p=0.001) were considered to be unfavourable factors for short-term response. Univariate analysis of unfavourable factors for longterm response showed that age ≥25 months (p=0.002), platelet count ≤6.9x109 /L (p=0.034), and Hb level >12.4 g/dl (p=0.001) were significant factors. Conclusion: These results suggest that in newly diagnosed ITP patients older than 25 months and/or with platelet count <6.9x109 /L, other therapeutic options such as corticosteroids alone or in combination with IVIG may be considered as initial therapy