Approximately 10 to 20 percent of children who present with ITP develop chronic ITP, defined as platelet count <100,000/ micro L lasting beyond 12 months from the time of presentation. Recently, it was found that apoptosis may be one of the factors controlling the survival and lifespan of the platelets in chronic ITP patients. High dose dexamethasone (HD-DXM) was suggested as one of the effective modalities of in treatment of chronic ITP. In this research we aim to detect the level of apoptotic platelets in children with chronic ITP and to evaluate the effect of high dose dexamethasone on platelets apoptosis in these children. Patients and methods: twenty- six chronic ITP patients and twenty-one age and sex matched healthy volunteers were exposed to quantitative assessment of apoptotic platelets. HD-DXM was given to the patients according to the treatment protocol with reassessment of the apoptotic platelets after the end of the treatment. Results: the mean levels of apoptotic platelets were significantly higher in patients before treatment compared to control and when compared to patients after treatment with HD-DXM. Conclusion: platelet apoptosis may play a role in the pathogenesis of chronic ITP with good impact of HD-DXM on decreasing apoptosis and increasing platelet count.