• The role of thrombocytopenia as a risk factor for intraventricular hemorrhage in infants of very low birth weight is unclear. This study investigates the relationship between the lowest platelet count and the occurrence of intraventricular hemorrhage in 302 consecutively admitted infants with birth weights under 1500 g. Intraventricular hemorrhage, which occurred in 90 infants (29.8%), was correlated with the lowest platelet count obtained during the first 4 days of life. In 27 infants with intraventricular hemorrhage, the lowest platelet count was less than 100×109/L. Statistical analysis of the data demonstrated that reduced platelet count was not associated significantly with intraventricular hemorrhage. Similarly, the severity of intraventricular hemorrhage did not correlate with the lowest platelet count. These data suggest that a reduced platelet count does not play a major role in the pathogenesis of intraventricular hemorrhage in infants of very low birth weight.