Prematurity and low birth weight adds to the risk of serious congenital heart disease in infants. It may also delay surgical intervention, especially when cardiopulmonary bypass is required, or wher an aortopulmnary shunt is necessary to maintain adequate oxygenation. In this setting, the neonatologists are faced with the challenge of accelerating the infant s growth to allow for early surgery. We describe the cases of two infants in whom and attempt to fortify the feeds was associated with necrotising enterocolitis, with a lethal outcome in one. The outcome suggests caution in fortifying feeds in premature infants with serious congenital heart disease.