The study aimed to examine the effect of the "Violence Reduction Psychoeducation Program (VRPP) for Students 11-18 Years Old" on the anger, violence, and aggression levels of students. "Quasiexperimental Designs with Pre-test and Post-test Control Group" were used in the study. The sample of the study consisted of 114 students studying in Selçuklar secondary school affiliated to Mersin Provincial Directorate of National Education in the 2018-2019 academic year. The program was applied to the experimental group for 8 weeks with 1 session per week and 60-70 minutes in the conference hall of the school. To test the effectiveness of the program, the "Continuous Anger and Anger Expression Style Scale," "Buss Perry Aggression Questionnaire" and "Aggression Scale" were used as measuring instruments. "Independent Sample T-Test," "Covariance Analysis" and "Two-Way Variance Analysis for Repeated Measurements" were used for data analysis. As a result of the research, it was observed that the program was effective in reducing the anger, violence, and aggression levels of the students and it was concluded that it is a valid and reliable program applicable to secondary school students in Turkey. Suggestions that such programs to prevent anger, violence, and aggression to be placed on the system of education and school curricula within the scope of preventive and developmental guidance and to be applied to students from an early age by the school psychological counselors have been made. It is thought that the program will contribute to the field of Psychological Counseling and Guidance as preventive guidance and will also be a pioneer in new studies in this field.