OBJECTIVE This study analyzed the factors that are associated with the need for packed red blood cell transfusions in premature infants in a neonatal intensive care unit. METHODS This study is a cross-sectional study of secondary data from premature infants who were admitted to a neonatal intensive care unit between 2008 and 2010. Premature infants with low birth weight were included. Packed red blood cell transfusion was the dependent variable. Pearson's Chi-square or Fisher's exact tests were used for data analysis, and the median, minimum, and maximum values were calculated. Prevalence ratios were calculated using the Poisson regression and Pearson correlation coefficient. Linear regression analyses were performed. P < 0.05 was considered to be significant. RESULTS We examined 254 premature infants, and 39.4% of this sample received packed red blood cells. Transfusions were 70% less prevalent in premature infants who were born at >32 weeks of gestation, and 191% more prevalent in infants who exhibited late-onset neonatal sepsis. The number of transfusions per patient was negatively correlated with gestational age and positively correlated with late-onset neonatal sepsis. A gestational age <32 weeks and late-onset neonatal sepsis explained 45% of the transfusions (p<0.0001). CONCLUSIONS Premature infants with a gestational age <32 weeks and who developed late-onset neonatal sepsis exhibited a greater need for packed red blood cell transfusions.