The relationship between nutritional status and intellectual capacity in 6-year-old children was investigated in 83 subjects of medium-high socio-economic status, without any apparent risk of malnutrition and normal or high intellectual capacity. Nutritional status was evaluated by measuring food consumption, anthropometrical measurements and biochemical indicators (iron status, red cell folate and total plasma homocysteine concentration (tHcy)). IQ was evaluated using the WPPSI test. The relationship between nutritional status and IQ was investigated by multiple linear regression analysis adjusting for socio-demographic variables and sex. There was a significant and positive relationship between iron intake and both total and non-verbal IQ. This was also the case for folate intake and both total and verbal IQ. The fact that these observations were made in children from a developed country, in which their energy and education requirements are met, suggests that their cognitive development may benefit from specific preventive nutritional interventions with these nutrients.