Background: Early and late-onset neonatal sepsis (EOS and LOS) are significant causes of morbidity and mortality in newborns. Accurate and timely diagnosis is critical for effective management. The Cluster of Differentiation 163 (CD163) level in the blood has emerged as a potential biomarker for sepsis, reflecting the immune response to infection. Objective: This study aimed to evaluate the role of CD163 levels in predicting neonatal sepsis and its correlation with other clinical and laboratory parameters. Methods: A comparative study was conducted involving 90 neonates divided into three groups: EOS, LOS, and a control group. Clinical data, presenting complaints, maternal risk factors, and laboratory findings were analyzed. CD163 levels were measured and correlated with clinical outcomes. Results: CD163 concentrations were markedly higher in both EOS and LOS cohorts relative to the control group. In the LOS cohort, CD163 levels demonstrated a positive association with platelet count and an inverse relationship with hemoglobin concentrations. No significant gender differences in CD163 levels were observed. Conclusion: CD163 serves as a critical biomarker for the prompt identification of neonatal sepsis, with a threshold value set at ≥ 4.5%. Its use in clinical practice could enhance early diagnosis and treatment as well as reduction of neonatal morbidity and mortality.