Background: Neonatal sepsis is life-threatening disease; it represents a big problem duo to its difficult diagnosis. It is associated with high mortality rate if not treated promptly. It is therefore very critical to do early diagnosis and initiate adequate therapy. Objective was to make a flow cytometric evaluation of CD11b expression on peripheral blood neutrophils for early and rapid diagnosis of neonatal sepsis. Methodology: our study was carried out on 70 neonates and subdivided into 2 groups, study group consisted of 50 neonates and control group consisted of 20 apparent healthy neonates, three ml of blood were collected for evaluation of CD11b expression by flow cytometry, CBC, CRP determination, and for blood culture. Results: there was a significant increase in percentage expression of CD11b on peripheral blood neutrophils in group I (sepsis group) more than group II (control group) , CD11b expression level in % on peripheral blood neutrophils record the highest sensitivity and specificity for diagnosis of neonatal sepsis followed by CRP. Blood culture recorded the least sensitivity and specificity. Conclusion: flow cytometric detection of CD11b on peripheral blood neutrophils is a useful technique for early and rapid diagnosis of neonatal sepsis.