During infancy different types of milk feeding can be used, i.e. breast milk, formula or cow's milk. In the Leiden Pre-School Children Study food intake and anthropometric data of four-, six- and nine-month-old infants were collected to study the influence of the type of milk feeding on the energy and nutrient intake on one hand and on height and weight on the other hand. All three different types of milk feeding were studied in the four-month-old infants. In the six- and nine-month-old infants food intake data of those breast-fed were not collected. No differences in energy intake and in height and weight were found between formula-fed infants and infants fed on cow's milk at the three age-levels. The influence on nutrient intake, on the contrary, was substantial. Compared to formula feeding, cow's milk feeding resulted in a significantly higher intake of protein, sodium, potassium, calcium and phosphorus and a significantly lower intake of linoleic acid, iron and ascorbic acid. Cow's milk feeding at four months was more prevalent among less educated mothers than among mothers with higher education. Breast feeding was strongly positively related to educational level of the mother at all three ages. It can be concluded that more information should be given about the advantages and disadvantages of different types of milk feeding especially to less educated mothers.