Abstract Aim: This study aimed to investigate the in-vitro platelet aggregation and secretion tests in children patients with Henoch-schöenlein Purpura that recently referred to as Ig A vasculitis Methods: This is a cross-section study that included 55 patients with Henoch-schöenlein Purpura and 31 healthy children as a control group. Children who have a history of drug use, chronic diseases, and bleeding diseases were excluded from the study. Complete blood count, thrombocyte aggregation, and secretion tests were studied in both groups. These tests were re-evaluated in remission of the disease. Results: It was found that epinephrine-stimulated platelet aggregation and collagen, epinephrine, ristocetin, arachidonic acid, standard dose thrombin, and high dose thrombin-stimulated platelet secretion results were lower in the patients with Henoch-schöenlein Purpura compared to the healthy control group in the acute period (respectively P=0.014, 0,003; 0,003; 0,027; 0,034; 0,010; 0,049). When the values of patients with Henoch-schöenlein Purpura in the acute period and the remission of the disease were compared, collagen-stimulated platelet aggregation and epinephrine-stimulated platelet secretion values were found to be lower in patients with patients in the acute period (P= 0.016; 0.039) Conclusion: Impairment in vitro platelet aggregation and secretion tests in the patients with Henoch-schöenlein Purpura suggest that the tendency to bleeding in these patients may be due to platelet impairment function. Key Words: Henoch-schöenlein Purpura, platelet aggregation tests, platelet secretion tests, children, Ig A vasculitis. What’s already known about this topic? There is a tendency to bleeding in Henoch Shcöenlein Purpura patients, such as gastrointestinal bleeding, nonthrombocytopenic system purpura. What does this article add? It was found that impairment in-vitro platelet aggregation and secretion tests in Henoch Shcöenlein Purpura patients.