Background: Sepsis is a systemic syndrome induced by infection and results in extensive inflammation, septic shock, multiple organ failure, and even death. The blood neutrophil - to - lymphocyte ratio (NLR) has been proposed as a marker of systemic inflammation since sepsis is characterized by an increase in neutrophils and a reduction in lymphocytes in the blood. This study aimed to evaluate the value of the neutrophil to lymphocyte and platelet -to- lymphocyte ratio as early diagnostic markers of sepsis and predict patient outcomes in the Pediatric Intensive Care Unit. Patients and methods: Sixty-six children aged 1 month to 16 years were admitted to the pediatric intensive care unit for early diagnosis of sepsis and prediction of patient outcomes at the Pediatric Intensive Care Unit, Zagazig University Hospital. Results: All patients in the non survivors group had positive blood cultures, and a greater percentage of patients had growth: denoting Staphylococcus aureus (57.6%), followed by Klebsiella (21.2%). The best cut-off of the NLR for the prediction of mortality among patients with sepsis was ≥6.8521, with a sensitivity of 78.6% and specificity of 78.9%. The best cut-off of the PLR for the prediction of mortality among patients with sepsis was ≥126.7365, with a sensitivity of 78.6% and specificity of 73.7%. Conclusion: PLR and NLR are dependable predictive indicators that are inexpensive and rapidly obtainable in the early detection of sepsis onset. They assist in identifying children at high risk for sepsis, predicting their mortality, and objectively monitoring clinical improvement.