Purpose: To investigate how a physical activity education program based on the teaching personal and social responsibility (TPSR) model affected disruptive behaviors in teenagers. Method: A total of 338 students (13-15 years old) from the 672 recruited completed a 4-month TPSR-model-based program during their physical education lessons. Disruptive behavior was recorded through systematic observation. Results: The students from the TPSR-model-based group reduced their violent behaviors (physical aggressions, verbal aggressions, interrupting, and total behaviors) after the intervention, whereas the control group remained the same. Conclusions: The TPSR school-based intervention was efficient in improving coexistence in terms of decreasing violent behaviors (physical and verbal aggressions) and undisciplined behaviors (continual interruptions of lessons) in students. The novel approach used to objectively assess emerging behaviors enriched the quality and validity of the quantitative data. Future research should address the use of objective assessment when conducting TPSR-model-based programs.