<![CDATA[Background: Adolescence is a transitional phase that is vulnerable to various risky behaviors, including premarital sex. Data shows an increase in the number of pregnancies and early marriages at the age of 15-19 years, both at the national, provincial, and city levels. The main factor behind this condition is the low understanding of adolescents regarding reproductive health. At State Vocational High School 4 Surakarta, informal findings indicate dating behavior that leads to physical contact, emphasizing the importance of educational interventions. The use of appropriate learning media, such as Index Card Match (ICM), is considered capable of increasing adolescent understanding in an interactive and interesting way. Pupose: To evaluate reproductive health education on preventing premarital sex using the index card match (ICM) method on students' knowledge. Method: Quantitative research with pre-experimental design using one-group pretest-posttest. Participants consisted of 57 female students of State Vocational High School 4 Surakarta who were selected by purposive sampling. Measurement of knowledge level was conducted before and after counseling using a questionnaire instrument and data analysis using a paired sample t-test. Results: Before the intervention, 75.4% of female students showed a low level of knowledge. After being given ICM education, 86% of respondents increased to the good category. Statistical tests showed a p value <0.05, meaning that there was a clear difference between before and after the intervention. Conclusion: Learning with the index card match method has a significant effect on efforts to develop adolescent knowledge about preventing premarital sex. Suggestion: Schools are expected to integrate the ICM method in reproductive health learning so that students better understand the risks and prevention of premarital sex interactively. In addition, parents should also play a more active role in providing sexual education to adolescents from an early age, so that they have the correct understanding and do not only rely on information from peers or social media. Keywords: Education; Index Card Matching (ICM); Knowledge; Premarital Sex Prevention; Reproductive Health. Pendahuluan: Remaja merupakan fase transisi yang rentan terhadap berbagai perilaku berisiko, termasuk seks pranikah. Data menunjukkan meningkatnya angka kehamilan dan pernikahan dini pada usia 15–19 tahun, baik di tingkat nasional, Provinsi, maupun Kota. Faktor utama yang melatarbelakangi kondisi tersebut adalah rendahnya pemahaman remaja mengenai kesehatan reproduksi. Di SMK Negeri 4 Surakarta, temuan informal mengindikasikan adanya perilaku pacaran yang mengarah pada kontak fisik, menegaskan pentingnya intervensi edukatif. Penggunaan media pembelajaran yang tepat, seperti Index Card Match (ICM), dinilai mampu meningkatkan pemahaman remaja secara interaktif dan menarik. Tujuan: Untuk mengevaluasi edukasi kesehatan reproduksi pencegahan seks pranikah menggunakan metode index card match (ICM) terhadap pengetahuan siswa. Metode: Penelitian kuantitatif dengan rancangan pre-eksperimen menggunakan one-group pretest-posttest. Peserta terdiri dari 57 siswi SMK Negeri 4 Surakarta yang dipilih secara purposive sampling. Pengukuran tingkat pengetahuan dilakukan sebelum dan sesudah edukasi menggunakan instrumen kuesioner dan analisis data menggunakan paired sample t-test. Hasil: Sebelum intervensi, 75.4% siswi menunjukkan tingkat pengetahuan yang buruk. Sesudah diberikan edukasi ICM, 86% responden mengalami peningkatan ke kategori baik. Uji statistik menunjukkan p-value < 0.05, berarti ada perbedaan yang terlihat jelas sebelum dan sesudah intervensi. Simpulan: Pembelajaran menggunakan metode index card match berpengaruh signifikan dalam upaya mengembangkan pengetahuan remaja tentang pencegahan seks pranikah. Saran: Pihak sekolah diharapkan dapat mengintegrasikan metode ICM dalam pembelajaran kesehatan reproduksi agar siswa lebih memahami risiko dan pencegahan seks pranikah secara interaktif. Selain itu, orang tua juga sebaiknya lebih berperan aktif dalam memberikan pendidikan seksual kepada anak remaja sejak dini, sehingga mereka memiliki pemahaman yang benar dan tidak hanya bergantung pada informasi dari teman sebaya atau media sosial. Kata Kunci: Edukasi; Index Card Match (ICM); Kesehatan Reproduksi; Pencegahan Seks Pranikah; Pengetahuan.]]>
