Objective To determine the association between direct costs for the initial neonatal intensive care unit hospitalization and 4 potentially preventable morbidities in a retrospective cohort of very low birth weight (VLBW) infants (birth weight <1500 g). Study design The sample included 425 VLBW infants born alive between July 2005 and June 2009 at Rush University Medical Center. Morbidities included brain injury, necrotizing enterocolitis, bronchopulmonary dysplasia, and late-onset sepsis. Clinical and economic data were retrieved from the institution's system-wide data and cost accounting system. A general linear regression model was fit to determine incremental direct costs associated with each morbidity. Results After controlling for birth weight, gestational age, and sociodemographic characteristics, the presence of brain injury was associated with a $12 048 ( P = .005) increase in direct costs; necrotizing enterocolitis, with a $15 440 ( P = .005) increase; bronchopulmonary dysplasia, with a $31 565 ( P < .001) increase; and late-onset sepsis, with a $10 055 ( P < .001) increase. The absolute number of morbidities was also associated with significantly higher costs. Conclusion This study provides collective estimates of the direct costs incurred during neonatal intensive care unit hospitalization for these 4 morbidities in VLBW infants. The incremental costs associated with these morbidities are high, and these data can inform future studies evaluating interventions aimed at preventing or reducing these costly morbidities.