ABSTRACT Background: Adolescence is a transitional period between the time of children with adulthood. There are still many found little regard for teens on health on reproductive, will consequently risk against the occurrence of an increase in diseases, among others; Sexually Transmitted Infections (STI). Methods: This type of research is the pre-design experiments using One-Shot Case Study, measured through a questionnaire. Class X student population of 33 students, XI IPS 2 of 26 students, and XII IPS 1 of 29 students. With a variable level of knowledge about reproductive health education, sexually transmitted diseases, prevention and the introduction of infectious disease symptoms, processed and analyzed using descriptive statistics. Results: The results of the research on reproductive health education on class X most (63, 64%) have moderate levels of knowledge about sexually transmitted diseases in class XI IPS 2 most (73%), 8 have a level of knowledge, level of knowledge about the prevention of infectious diseases and the introduction at the XII 1st most IPS (58, 62%) have moderate levels of knowledge. Conclusion: the level of knowledge of students of SMK Kanjeng Sepuh Gresik about adolescent reproductive health is on a category of being. Therefore the expected reproductive and Sexual health education as a subject/local content through the media of the school as a proper step as a medium of education can provide information on sexual and reproductive health is right for teens.