A cross-sectional study with a self-administered questionnaire based on the theory of planned behavior to analyze the factors associated with the intention of participating in peer education activities to prevent drug abuse among adolescents in high schools. A total of 854 students from school which held peer education activities participated in this study. This study found that 87.5% of students had the intention to participate in peer education activities. Of the eight variables which were significant in the chi-square analysis, only four were significant following the logistic regression test, namely attitude, normative belief, subjective norm, and perceived behavioral control. The students had good support from individual and social factors in drug abuse prevention activities in their school. The support of the school and related stakeholders is still needed to make an effective program of drug abuse prevention by peer- educator.