Endocan is a specific endothelial mediator involved in the inflammatory response. Its role in the diagnosis of sepsis has been studied in adult patients and late onset neonatal sepsis. The clinical signs of early onset sepsis (EOS) are nonspecific and routinely used biomarkers, such as C-reactive protein and procalcitonin, have low sensitivity, specificity and positive predictive value. Endocan could be useful as a biomarker for diagnosis of EOS, but at present normal range values for this molecule have not been reported. The aim of this study is to establish the normal values range for serum endocan in term and preterm newborns without risk factors for EOS and to characterize the variation pattern of its levels at different postnatal moments.Mean endocan serum concentration (ESC) was measured in term and preterm newborns without clinical suspicion of EOS at different moments from birth.ESC (ng/mL) in term newborns was 1.74+/-0.13 on day 1 and 2.02+/-0.41 on day 3 respectively, (p=0.09). In preterm newborns ESC (ng/mL) was 2.02+/-0.11 and 1.97+/-0.18, (p=0.8) for day 1 and 3 respectively. ESC was not significantly influenced by sex, mode of delivery, evidence of fetal distress or presence of minor birth trauma.ESC (ng/mL) between the first and third day of life in either term or preterm infants don't appear to be significantly influenced by factors that are associated with elevation of inflammatory markers, thus using this biomarker for the diagnosis of EOS might reduce the false positive results.