<![CDATA[Background: HIV/AIDS is a disease that spreads widely in the world which the number of sufferers are constantly increasing. Most of the people with HIV/AIDS are on the productive age range, including the students, that were influenced by risk behavior among adolescents. The high risk of HIV transmission is affected by the behavior, including syringe usage and free sex.Methods: The research was an observation descriptive with a cross sectional approach. Population of this research were 270 people which the samples were 73 people with the selection of samples was performed using stratified random sampling technique and purposive sampling. Data was collected by using a questionnaire.Results: The result of the research are 73 students in SMA Negeri 9 Palu were in   the category of good knowledge with percentage at 74,0%, 19,2% respondents   were categorized in the group of moderate knowledge and category of less           knowledge was 6,8%. In addition to the students’s attitude, moderate category    was to 87,7% and 12,3% respondents were categorized in the group of less         behaviour. Student action lied on good category were as many as 83,6% and      moderate category were as many as 16,4%. Conclusion : Overview of student behavior in SMA Negeri 9 Palu on the prevention of HIV/AIDS as a whole were quite good, but the stakeholder of the school should pay more attention to students, in order to refrain from risky behavior to HIV/AIDS infection. Keyword: Behavior, knowledge, attitude, act, HIV/AIDS Latar Belakang: HIV/AIDS merupakan penyakit yang tersebar di seluruh dunia dan jumlah penederitanya semakin hari semakin meningkat. Penderita HIV/AIDS tersebut sebagian besar berada dalam rentang usia produktif, termasuk para pelajar, hal ini dipengaruhi oleh perilaku beresiko di kalangan remaja. Resiko tinggi penularan HIV diketahui berasal dari perilaku, termasuk penggunaan jarum suntik dan seks bebas.Metode: Jenis penelitian ini adalah observasi yang bersifat deskriptif dengan pendekatan cross sectional. Populasi penelitian sebanyak 270 orang, besar sampel sebanyak 73 orang. Pemilihan sampel dilakukan menggunakan teknik Stratified Random Sampling dan Purposive Sampling. Pengambilan data dilakukan dengan menggunakan kuesioner.Hasil: Dari 73 orang siswa SMA Negeri 9 Palu, yang memiliki kategori pengetahuan baik sebesar 74,0%, kategori pengetahuan cukup sebesar 19,2% dan kurang sebesar 6,8%. Sikap siswa berada pada kategori cukup sebesar 87,7% dan kategori kurang sebesar 12,3%. Tindakan siswa berada pada kategori baik sebesar 83,6% dan kategori cukup sebesar 16,4%.Kesimpulan: Gambaran perilaku siswa SMA Negeri 9 Palu terhadap pencegahan HIV/AIDS secara keseluruhan sudah cukup baik, namun kepada pihak sekolah harus tetap memperhatikan siswa agar tidak melakukan perilaku beresiko terhadap penularan HIV/AIDS.  Kata Kunci: Perilaku, pengetahuan, sikap, tindakan, HIV/AIDS]]>
