This study aimed to test the effectiveness of the Addiction Prevention Training Program (APTP) of Turkey, (Turkiye Bagimlilikla Mucadele Programi) and gather the perspectives of students and stakeholders about the program. APTP is an intervention program designed and implemented by the Turkish Green Crescent Society, which aims to increase knowledge and emotional awareness about addiction among primary, secondary, and high school students. APTP consists of 4 modules: tobacco, alcohol, drug, and technology addiction, and the knowledge and emotional awareness of each of these were tested. In the first phase of this mixed-method study, 2x3 Split Plot Factorial Design was used. A total of 5451 randomly assigned students (primary=600, secondary=2496, and high school=2355) participated in the experimental and control groups. In the second phase, focused group interviews with students (n=55), parents (n=26), and branch teachers (n=18); and individual interviews with school counselors (n=3) and principals (n=3) were conducted. The opinions of the participants regarding the training were analyzed using descriptive analysis. Results of the Two-way Analysis of Variance (ANOVA) revealed that receiving APTP had a significant effect, mostly on improving the knowledge level of students about tobacco, alcohol, drug, and technology addiction. Qualitative findings supported the quantitative results that parents, teachers, school counselors, and school principals reflected the increased knowledge of students about addiction.