Background: Neonatal Sepsis is a major problem in newborn nurseriesbecause of the difficulty in early diagnosis and because of high morbidityand mortality.The objective of this study was to investigate whether urinary nitric oxide(NO) level could be useful for the diagnosis of infected newborns.Methods: Urinary NO are measured for newborns with sepsis on the 1stand on the 4th day who were group of study (group I) and compared withage matched healthy control (group II).Results: Ninety percent of the septic group showed increase in theurinary NO level during sepsis, while in the control group there wasdecrease in the NO level, the mean of NO on the 1st day in group (I) was(67.13 ± 50.03) and was (78.52 ± 36.80) in group (II), the mean of NO onthe 4th day was (97.49 ± 65.75) while in group (II) was (56.87 ± 29.62)and the percentage change from 1st day was (76.47 ± 103.33) in group Ibut was (-30.81 ± 25.77) in group II.Conclusion: Urinary NO level which are quick and easy to measure arehigher in the infected newborns as compared with controls. Thesensitivity of the test is good and the serial measurements of NO isrecommended to early detection of sepsis.