It has been recommended that U.S. children increase their dietary intake of fruits and vegetables. Measuring diets of children to support and evaluate nutritional interventions can be a difficult task, however. We administered to 97 parents of children age 6-10 years a food frequency questionnaire on their children's usual dietary intake over the previous 3 months. We then compared these reports by parents of their children's intakes of fruits and vegetables, and the derived estimates of intake of carotenoids and vitamins C, A, and E, with the children's serum levels of carotenoids and vitamins C, A, and E. The dietary reports of intakes of 35 fruits and vegetables showed Spearman rank-order correlations of 0.30 with serum carotenoids and 0.34 with serum vitamin C. Children in the highest quartile for intake of fruits and vegetables according to their parents' food frequency reports had 35% higher carotene levels and 31% higher vitamin C levels in their serum than did children in the lowest quartile for intake of fruits and vegetables. We conclude that parental reports of young children's diets using food frequency methods are accurate enough to be useful in nutritional screening and dietary surveillance of fruit and vegetable intake.