Hemophilia A is X-linked coagulation disorder occurs due to mutation in the gene responsible of Factor VIII production.Providing the deficient factor VIII to the patient (whether plasma derived or synthesized) is a must. Formation of Factor VIII inhibitors one of the most complex side effects of treatment. The present study was conducted on 30 pediatric hemophilic patients, all are males to evaluate risk factor for inhibitors development. Eight patients showed positive factor VIII inhibitors. Treatment of six of them were with increasing the dose of the replacement factor (Factor VIII or Cryo), and three patients needed factor VII to be prepared for surgery and to treat acute bleeding episodes. This study revealed that there is no relation between type of therapy used and occurrence of inhibitors, also1ry prophylaxis treatment has higher risk of inhibitors development (five of six patients), there is no relation between age, sex, duration or timing of treatment and inhibitors development. Also inhibitors develop more commonly in patients with FVIII level <1%.