This study aimed to compare the effectiveness of Mentalization-Based Therapy and Schema Therapy on emotion processing styles and dysfunctional beliefs in adolescents with risky behaviors. The research method was quasi-experimental with a pretest-posttest-follow-up design and a control group. The statistical population consisted of female high school students in the 14th district of Tehran Province during the academic year 2024-2025 who exhibited risky behaviors. G*Power software version 1.3 was used to calculate the sample size. According to the research design, 15 participants were assigned to each experimental and control group, totaling 45 participants selected through purposive sampling and then randomly assigned to two experimental groups and one control group. The data collection instruments included Baker’s Emotion Processing Questionnaire (2007), the Dysfunctional Beliefs Questionnaire for Adolescents (Bernard, 1988), and the Risk-Taking Questionnaire for Iranian Adolescents (Mohammadi Iranzadeh & Ahmadabadi, 2008). Data were analyzed using repeated measures ANOVA and Bonferroni post hoc tests with SPSS version 28. The results indicated that both Mentalization-Based Therapy and Schema Therapy were effective on emotion processing styles and dysfunctional beliefs in adolescents with risky behaviors (p ≤ 0.001). MANOVA revealed significant differences among groups in emotion processing components; the Mentalization group performed better in components such as emotional acceptance and emotion regulation (p = 0.001). Finally, MANOVA results also showed significant differences between groups in dysfunctional belief components (p = 0.002). Based on the findings of the present study, the effectiveness of these two therapies in improving emotion processing styles and dysfunctional beliefs in adolescents with risky behaviors informs clinicians in selecting therapeutic approaches tailored to the specific psychological needs of high-risk populations.