Perilaku agresif merupakan kecenderungan perilaku yang niatnya untuk menyakiti orang lain, baik secara fisik maupun psikologis. perilaku agresif juga ditemukan di sma negeri 1 tarakan, peserta didik yang melakukan tindakan perilaku agresif mempunyai pandangan yang salah terhadap lingkungan atau situasinya. perilaku agresif termasuk bentuk perilaku negatif yang timbul karena adanya rangsangan, terutama rangsangan dari lingkungan yang sering kali mengakibatkan dampak yang lebih besar. upaya yang dapat dilakukan dalam menurunkan perilaku agresif adalah menerapkan layanan konseling kelompok dengan teknik rational emotive behavior. teknik rational emotive behavior membantu seseorang menyadari bahwa mereka dapat hidup lebih rasional dan produktif, mengubah kebiasaan berpikir, perilaku yang merusak diri sendiri, serta mengurangi perasaan yang tidak diharapkan. penelitian ini bertujuan untuk mengetahui pengaruh teknik rational emotive behavior terhadap perilaku agresif peserta didik di sma negeri 1 tarakan. jenis penelitian ini adalah kuantitatif, dengan pendekatan pre-experiment dan desain one-group pretest-posttest design. jenis pengambilan sampel dalam penelitian ini menggunakan teknik purposive sampling, dengan populasi sebanyak 405 peserta didik dan sampel berjumlah 5 peserta didik kelas x. teknik pengumpulan data dalam penelitian ini menggunakan instrument berupa skala likert tentang perilaku agresif. analisis data dengan statistik deskriptif dan inferensial menggunakan uji paired sample t-test. berdasarkan hasil penelitian ini, perhitungan uji paired sample t-test dengan nilai sig (2-tailed) sebesar 0,001 < 0,05 maka ho ditolak dan ha diterima, yang berarti terdapat pengaruh teknik rational emotive behavior terhadap perilaku agresif peserta didik di sma negeri 1 tarakan. kata kunci: perilaku agresif, rational emotive behavior (reb)

Aggressive behavior is a tendency to harm others, both physically and psychologically. such behavior was observed among students at sma negeri 1 tarakan, where it was noted that those exhibiting aggressive tendencies had a distorted view of their environment or situation. aggressive behavior often arose due to environmental stimuli, leading to significant negative impacts. one effective intervention to reduce aggressive behavior was by implementing group counseling services using the rational emotive behavior technique (rebt). rebt helped individuals realize they lived more rationally and productively, changed self- destructive thinking habits, and reduced unwanted emotions. this research aimed to determine the effect of the rational emotive behavior technique on the aggressive behavior of the students at sma negeri 1 tarakan. the research employed a quantitative approach with a pre-experimental design, specifically a one-group pretest-posttest design. the sampling method was purposive, selecting 5 students from class x out of a population of 405 students. data collection involved a likert scale instrument measuring aggressive behavior. the data were analyzed using descriptive statistics and inferential statistics, specifically the paired sample t-test. the results indicated a significant effect of the rational emotive behavior technique on reducing aggressive behavior. the paired sample t-test calculation yielded a sig (2-tailed) value (p) of 0.001, which was less than the significance level (a) of 0.05. this result revealed that the null hypothesis (ho) was rejected, and the alternative hypothesis (ha) was accepted, confirming the positive impact of the rational emotive behavior technique on the aggressive behavior of the students at sma negeri 1 tarakan.