© 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.Aim: Peri-/intaventricular hemorrhage (P/IVH) is a common condition in preterm neonates and is responsible for substantial adverse neurological outcome especially in extremely low birth weight infants. As hematocrit after birth is a surrogate marker for blood volume, this study aimed to evaluate the effect of initial hematocrit values after birth on P/IVH development in extreme low birth weight (ELBW) neonates. Patients and methods: A prospective cohort analysis of 92 eligible ELBW neonates was performed. The relationship between initial hematocrit values in ELBW neonates after birth and subsequent development of P/IVH was examined. Results: Twenty-nine of 92 infants developed P/IVH. There were significant differences in initial Hct and maximum carbon dioxide (max PCO2) in the first 3 days levels in the P/IVH group compared with no P/IVH group. Initial Hct level at birth in the P/IVH group were significantly lower than the no P/IVH group while max PCO2 in the first 3 days were found to be significantly high in the P/IVH group. There were no significant differences in other baseline demographic, perinatal, and neonatal characteristics while in univariate analysis, higher gestational age and initial Hct were associated with decreased likelihood of P/IVH. In multiple regression analysis after adjustment, only initial Hct remained significantly associated with P/IVH. There was no difference between the population by subgroups of IVH (IVH I–II and IVH III–IV) according to hematocrit and the severity of IVH. Conclusion: Higher initial Hct at birth is associated with decreased P/IVH in ELBW infants. We hypothesized the argument that ELBW infants who have lower initial Hct at birth have less suboptimal volume status that predisposing lower cerebral blood flow and the resultant decrease in cerebral blood flow precede the development of P/IVH.