Background: Hyperglycemia commonly occurs in any cases of critical illness, after subsiding of acute illness, blood glucose became normal. Critical illness hyperglycemia caused due to stress and inflammation. Disease severity considered the main risk factor for hyperglycemia development. Objectives: This study was done to evaluate the association between stress hyperglycemia on patient's morbidity and mortality in the pediatric intensive care unit. Patients & Methods: This cohort study was carried out in the Pediatric Intensive Care Unit (PICU), Zagazig University Hospitals including 96 children who admitted to PICU units, during the period from October 2018 to January 2019. we studied the correlation between stress hyperglycemia with morbidity and mortality in the pediatric intensive care unit Results: The best cutoff of blood glucose in prediction of poor outcome in the studied patients is ≥ 121 mg/dl with area under curve 0.702, sensitivity 72.7%, specificity 64.7%, PPV 21.1, NPV 94.8, positive ratio 2.06, negative ratio 0.42 with accuracy 65.6% (p<0.05). Conclusions: Stress hyperglycemia is not a benign condition and its occurrence carries a poor prognosis among critically ill patients as proved by clinical findings, laboratory parameters, and mortality.