Background Neonatal sepsis is a complex syndrome which is characterized by systemic inflammatory response. The high mortality rate of neonatal sepsis is contributed to late diagnosis and improper management. Aim of the Work The aim of this research is to examine the diagnostic utility of miR-34a in newborns with sepsis (who were newly diagnosed according to the clinical sepsis score and the hematology score of sepsis) and compare them to neonates without sepsis by using real-time PCR. Patients and Methods This study was conducted on 70 neonates from NICU of Ain Shams University hospital and permitted by Ain Shams ethical committee. Neonates were classified into two groups: 35 neonate with sepsis and 35 neonate without sepsis. In consideration, these neonates’ ages were ≥ 35 weeks, had no Congenital anomalies, Chromosomal abnormalities and had not been given any kind of antibiotics before obtaining blood specimens from them. Moreover, the study didn’ t include neonates with an inborn error of metabolism or any surgical procedures. Neonates without sepsis and neonates with sepsis were matched in terms of gender and age. In our study, blood samples of 2 ml were withdrawn from patients (within 72 hours from suspecting the diagnosis of neonatal sepsis) and from the control at matched gestation and postnatal ages, then patients were followed up. Results the obtained results showed that, the expression level of miR-34a was reduced by 5.2-fold in neonates with sepsis, with a P value of 0.001. Additionally, a negative correlation was detected between miR-34a expression level and either the clinical sepsis score (p = 0.163) and the hematology score (p = 0.122), and also a significant correlation was detected between the clinical sepsis and hematology scores in neonates with sepsis (p = 0.047). The study observed that, the miR-34a could discriminate neonates with clinical sepsis score, the biomarker sensitivity and specificity were 80% and 70%, respectively. In addition, the calculated sensitivity and specificity of miR-34a to discriminate neonates with hematology score were 85% and 87%; respectively. The cut-off value was <0.04 . Conclusion Based on the obtained results, there is a significant difference between the serum expression level of miR-34a and either the clinical sepsis score and hematology score . the lower expression level of miR-34a was detected in neonates with CSS >10. Similarly, the lower expression level of miR-34a was detected in neonates with high hematology score >4.