Health literacy (HL) in children is essential for healthy decision-making from early on. At six Austrian elementary schools, all children (aged 6-11 years) received 3 years of health education (HE). The participating schools were equipped with teaching materials to convey lessons in a child-oriented way. The teachers were professionally accompanied during the implementation process and received specific training. HL and its subprocesses (obtain, understand, comprehend and apply) in children >8 years were measured with a standardized test (QUIGK-K) after 1, 2 and 3 years of education and compared with values from two comparison schools without such lessons. t-Tests showed a significant increase in HL at the end of the second year of HE. After this period, the children showed above-average values on all subprocesses of HL and performed better than children without HE. The third year did not lead to a further increase. Hence, child-oriented HE is suitable to promote HL in elementary school students within 2 years. It is therefore recommended to start HE as early as possible in order to lay the foundation for a long and healthy life.