In a randomised double blind trial, the effect on growth and clinical status of a nutrient enriched 'post-discharge' milk formula versus a standard term formula, was compared in 32 exclusively bottle fed preterm infants. The formulas were used as the sole milk intake up to a postnatal age of 9 months. Significant increases in linear growth and weight gain were observed in the infants who received the enriched diet. There were no differences in vomiting, posseting, or bowel habit between the groups. Formula volumes ingested were similar between diet groups, indicating that the difference in formula composition did not affect the infants' regulation of intake. These preliminary data suggest that there is a role for specially designed formulas for preterm infants after discharge from hospital.