 Rationale Neonatal sepsis is an important determinant of adverse neurodevelopmental outcome Adams-Chapman 2006, Stoll 2004. A recent meta-analysis estimated that neonatal sepsis more than doubled the risk of adverse neurodevelopmental outcome in very-low-birth-weight VLBW infants OR 2.09 95CI 1.65-2.65, including cerebral palsy OR 2.09 95CI 1.78-2.45.Alshaikh 2013 When a baby with signs suggestive of sepsis, it is common practice to commence intravenous antibiotic treatment as soon as possible after cultures from blood and relevant additional sites have been obtained. However, cultures remain negative in an important subgroup of babies treated for sepsis, despite convincing clinical andor laboratory signs of sepsis being present. Although there is some evidence to suggest that long-term outcomes following neonatal sepsis may differ according to whether or not the diagnosis was confirmed by culture,Stoll 2004, Schlapbach 2011 to the best of the investigators knowledge a direct comparison between these groups has never been made. Greater understanding of the impact of culture-positivity on long-term outcomes in the setting of clinical neonatal sepsis is essential to better inform parents about the future prospects of their child and to guide patient follow-up. 