The aim of this paper is to confirm the effectiveness of the education program for high school students on healthy nutrition for newborns, infants, and young children. A structured education program of four lessons on early child nutrition was created for high school students. The education program was presented to the Commission for the Protection and Promotion of Breastfeeding of the Ministry of Health of the Republic of Croatia and was corrected according to the Commission’s instructions. In accordance with the approval of the Ministry of Science and Education, non-institutional teaching according to the mentioned program was carried out on a trial basis in the final grades in three high schools of the Bjelovar-Bilogora County: Čazma High School, Bartol Kašić Grubišno Polje High School and August Šenoa Garešnica High School. Adult students personally gave informed consent to participate in the research, and for underage students parents gave consent. The supervisors of the supervised peer education were students of the first and second year of the professional study of Nursing at the Technical College in Bjelovar. They were prepared for such an activity with the help of the education program organized at the Techical College. Classes were supervised by supervisors who followed the work of student educators. The effects of the education were measured by a validated Questionnaire of the intentions, attitudes and knowledge of pupils and students about breastfeeding (BIAKQ questionnaire). The intentions, attitudes and knowledge of high school students about the natural nutrition of newborns and young children were measured immediately before and after the end of the education, and the difference in the results confirmed the effectiveness of the education.