Surgical Treatment of congenital heart disease in children often requires CPB (Cardiopulmonary bypass) and myocardial ischemia which can induce post cardiac surgery systemic inflammatory response that can lead to organ dysfunction and morbidity and it also induces a systemic cytokine release. The beneficial effect of steroid administration before cardiopulmonary bypass (CPB) to attenuate the post-pump syndrome has long been investigated. Steroids have an equal and even a synergistic effect with other agents, such as aprotinin, in blunting the inflammatory response. Several investigations have shown that steroid pretreatment modulates different aspects of the inflammatory response and have a favorable effect on the clinical outcome. Hyperglycemia is a well-known side effect of glucocorticoid use. Debate exists about the positive effects of steroid use during CPB in pediatric patients and whether the potential positive effects of corticosteroid treatment during CPB surgery outweigh the potential adverse effects, such as hyperglycemia.Thus, the aim of the current study is to assess the effect of high dose and low dose methylprednisolone on stress and inflammatory response of cardiopulmonary bypass and its reflection on glucose homeostasis in acyanotic pediatric cardiac surgery.