Objective: To asses the role of Triggering receptor ex-pressed on myeloid cells-1 (TREM-1) as a potential early diagnostic marker of neonatal sepsis. Methods: Studied neonates were evaluated for sepsis using clinical and laboratory measures. sTREM-1 was mea-sured in the serum by Enzyme Linked Immunosorbant Assay (ELISA) on admittion & 48 hour after antibiotic therapy. Another 10 blood samples from healthy neonates age & sex matched to cases were analysed for sTREM-1 as a control group. Results: Baseline sTREM-1 levels were significantly elevated in septic neonates (10 11. 1±594.93pg/mL) compared to controls (136.6±41.3pg/mL) & it was significantly decreased 48h after antibiotic therapy compared to baseline sTREM-1 level. sTREM-1 was increased in culture positive & culture negative cases with no significant difference between them. Septic preterm neonates had significantly higher sTREM-1 compared to full term neonates. sTREM-1 was significantly higher in neonates with early onset sepsis than late onset sepsis neonates. The cutoff value of 250pg/mL could be diagnostic for neonatal sepsis (NS) with 97.1% sensitivity and 90% specificity (AUC, 0.97). Conclusion: High serum sTREM-1 could be considered an early diagnostic marker of neonatal sepsis.