We investigated and evaluated the demographics, clinical and laboratory features, treatment responses, and disease duration of 25 children with immune thrombocytopenia (ITP) eligible for detection of antiplatelet antibodies. We found that patients without antecedent of preceding infection (API) were more likely to have anti-GPIa/IIa than those with API (42.9% vs. 5.5%, P=0.048). Age groups of <2 years and 2 to 10 years were more likely to show response (R) or complete response (CR) to given treatments, whereas none of the patients whose onset age >10 years showed R or CR to given treatments (88.9% and 100% vs 0%, P=0.001). The percentage of newly diagnosed ITP was higher in age groups of <2 years (100%) and in 2 to 10 years (90%) than the age group of >10 years (16.7%, P=0.001). Patients without API (71.4%) were more likely to develop chronic ITP than those with API (5.6%, P=0.002). In conclusion, younger age was a favorable prognostic factor, especially in patients <2 years of age with respect to treatment responses and disease duration. In addition, API was associated with a short disease course as well as absence of anti-GPIa/IIa.