Objective: To assess the impact of nutrition counselling given to 7.5-to 9-y-old children and their parents on children's nutrition knowledge and nutrient intakes. Design and subjects: The study children are participants in a prospective, randomised STRIP study (Special Turku Coronary Risk Factor Intervention Project for Children), whose aim was to decrease the intakes of saturated fat and cholesterol while increasing the intake of unsaturated fat in the intervention children from the age of 7 months onwards. Nutrition counselling was given only to the parents until the child's age of 7 y. Nutrition knowledge and nutrient intakes (total energy, total fat, saturated fat, unsaturated fat and sodium) were studied in a time-restricted cohort of 47, 7-y-old intervention and 51 control children. Thereafter, nutrition counselling was given both to the children and parents. Children's nutrition knowledge and nutrient intakes were measured again at the age of 9 y. Results: Biannual nutrition counselling given to the intervention children and the parents maintained the differences in saturated fatty acid intake attained during the intervention given to the parents alone (11.5 vs 13.3 E% (percent of energy intake), at the age of 7 y, Po0.01; 11.1 vs 13.4 E% at the age of 9 y, respectively; Po0.01). The intervention children used more polyunsaturated fatty acids at the age of 9 y than the control children (5.7 vs 5.1 E%, P ¼ 0.05). At 7 y, the intervention and control children had similar nutrition knowledge scores (total knowledge score 12.9 vs 12.0, respectively, P ¼ 0.13). After 1.5 y of nutrition intervention, at 9 y, the intervention children's nutrition knowledge was higher than that of the controls (total nutrition score 16.5 vs 13.2, respectively, Po0.001) and the ability to explain the reasons for their picture choices in the nutrition knowledge test had increased. Conclusion: This study showed that only a relatively short period of counselling with low input is needed to increase in children's nutrition knowledge and ability to explain nutrition-related subjects if advice has first been given to the parents and if the parents have received reinforcement and concrete help with parent-child communication after their children have been involved in the counselling. The differences attained in nutrient intake could also be maintained.