Background: Mean platelet volume (MPV) is a measure of platelet volume. It reveals the presence of inflammatory burden and disease activity in many diseases. Serum uric acid (SUA) is one of the most important antioxidants in human biological fluids and is responsible for neutralizing > 50% of the free radicals in the human blood. For this reason, it was thought that the antioxidant effects of SUA could increase the life expectancy and/or reduce the incidence of malignancy. Objectives: To determine the role of mean platelet volume (MPV) and serum uric acid (SUA) level in the diagnosis of neonatal sepsis (NS). Methods: This case-control study was done on 80 newborns divided into 3 groups: group A (n ¼ 22): clinical NS, group B (n¼18): Proven NS and Group C (n¼40): apparently healthy control. All patients in the study were subjected to adequate assessment of history, full clinical examination, complete blood count including MPV, C - reactive protein (CRP), blood culture in CRP positive cases, and SUA level at the time of diagnosis of sepsis. Results: Septic neonates showed statistically higher values of MPV and statistically lower levels of SUA than the control group.The diagnostic cut-offvalues of MPV and SUA for NS were 10.2 fL, and 3.70mg/dL, respectively. Conclusions: MPV could be assessed in the early diagnosis of neonatal sepsis while SUA level has lower sensitivity in neonatal sepsis