Abstract. Adolescence is a critical period in humans in terms of physical, psychosocial, cognitive, and emotional development, especially for the reproductive system. Adolescents must be prepared to face reproductive maturation so they need some information to solve the change in their bodies. Conducting health education about reproductive health is very important as an effort to increase knowledge in dealing with puberty. The reproductive health education program for adolescents facing puberty is one solution that can be done to increase adolescents’ knowledge about reproductive health. This activity aims to increase adolescents’ knowledge about health reproductive in adolescence. The method used was a quasi-experiment research design with a group pretest and posttest approach. The population in this program was elementary school students in grades 4 and 5 at SDN Banyuurip Yogyakarta with a total sample of 38 students and a purposive sampling technique with inclusion criteria for children aged 10-14 years. Then, the data was analyzed by using a paired t-test. The results showed that there was a significant difference in students’ knowledge levels before and after the education was implemented. Before the reproductive health education, the respondents' knowledge level was mostly in the less category of 52%, sufficient category of 42%, and good category of 5%. After the reproductive health education was carried out, most of the students had good knowledge of 71%, sufficient knowledge of 29%, and no students had insufficient knowledge. Other results showed the pre-test mean scored 76.58 and post-test mean scored 83.16, median pretest and post-test scored 80 and 90. The results of the paired t-test obtained a p-value of 0.049 <0.005. Therefore, it can be concluded that there is an effect of reproductive health education on Banyuurip elementary school children of Yogyakarta. Conclusion: Reproductive health education is proven to increase students’ knowledge level in dealing with puberty and care for reproductive organs.