Studying the correlative structure of young children's food preferences may help us to understand the influences on the development of eating habits. We investigated patterns of food preferences in 214 same-sex twin pairs aged 4 to 5 years. Mothers completed a questionnaire of their children's likes and dislikes for 94 common foods. The proportion of children having tried each food, and their liking for it, were examined. These two measures were strongly positively correlated (r=0.61). Principal components analysis was used to examine the inter-relationships among preferences for 76 foods that had been tried by at least 75% of the children. Four factors emerged, interpreted from food factor loadings as "Vegetables", "Desserts", "Meat and Fish", and "Fruit", explaining 24% of the variance. Thus, children tended consistently to like or dislike foods within each of these factor categories, independently of patterns of liking in the other factors. Factor loadings were unrelated to average liking for or likelihood of exposure to these foods. The distribution of factor loadings refutes the common assumption that simple sensory properties such as sweetness, saltiness or fattiness predict food preferences. Instead, a preference structure may develop for more complex multimodal sensory syntheses, which could have both biological and learnt bases. Future work comparing the food preference structure of mono- and dizygotic twins should help determine the relative contribution of genetic and environmental influences.