A systematic literature search identified studies validating the methodology used for measuring the usual dietary intake in infants, children and adolescents. The quality of each validation study selected was assessed using a European micronutrient Recommendations Aligned-developed scoring system. The validation studies were categorised according to whether the study used a reference method that reflected short-term intake ( < 7 d), long-term intake ( > or = 7 d) or used biomarkers. A correlation coefficient for each nutrient was calculated from the mean of the correlation coefficients from each study weighted by the quality of the study. Thirty-two articles were included in the present review: validation studies from infants (1-23 months); child preschool (2-5 years); children (6-12 years); adolescents (13-18 years). Validation of FFQ studies in infants and preschool children using a reference method that reflected short-term intake showed good correlations for niacin, thiamin, vitamins B6, D, C, E, riboflavin, Ca, K, Mg, Fe and Zn (with correlations ranging from 0.55 for vitamin E to 0.69 for niacin).Regarding the reference method reflecting short-term intake in children and adolescents, good correlations were seen only for vitamin C (r 0.61) and Ca (r 0.51). Using serum levels of micronutrient demonstrated that the 3 d weighed dietary records was superior to the FFQ as a tool to validate micronutrient intakes. Including supplement users generally improved the correlations between micronutrient intakes estimated by any of the dietary intake methods and respective biochemical indices.