Intraventricular hemorrhage (IVH) is a multifactorial disorder, the most important risk factors of which are prematurity and low birth weight. Disturbances in cerebral blood flow, inherent fragility of the germinal matrix vasculature, and platelet/coagulation disturbances are the 3 major pathogenic mechanisms. In this context, we investigated the role of platelet indices and several maternal and neonatal characteristics in the development of IVH through a retrospective cohort analysis of 130 extremely premature neonates, 24% of whom presented with severe IVH. There was a significant difference in platelet counts between the IVH and the control group on the first day of life (P=0.046). Presence of IVH was linked with lower birth weight (P=0.006) and lower gestational age (P=0.001). Platelet count on the first day of life was positively correlated with survival (P=0.001) and, along with platelet mass, was indicative of the worst IVH grade recorded for each neonate (P=0.002 and 0.007, respectively). Prolonged prothrombin time was also correlated with IVH (P<0.001), but factor analysis supported no prominent role. Maternal medications seem to play a minor role as well. In conclusion, IVH in extremely premature infants cannot be solely explained by platelet parameters, and further studies are required to determine the relationships between IVH, platelet indices, and outcomes.