Disciplining requires the use of certain techniques and methods. Some techniques and methods are more efficient than the others. The preventive system represents education and disciplining of young people without the use of punishment. Don Bosco emphasizes the upbringing and integral development of the individual and his personality with the methods of the preventive system. The main goal of this work was to examine the teachers' opinions about how the preventive educational system of Don Bosco's pedagogy affects the discipline of the students of the Salesian Elementary School in Zagreb. More specifically, how the implementation of the preventive educational system reflects on the students and their attitude and behaviour towards fulfilling their obligations, towards their teachers, colleague students and other school staff. The theoretical part of the work deals with explaining the concept of discipline and positive discipline, specifying some disciplining techniques, and explains class management styles and ways of maintaining discipline in the class. Don Bosco's educational system of pedagogy is explained and Don Bosco's biography and the preventive system he founded are presented. It explains what an oratory is, how it functioned before and how it functions today. The empirical part of the paper presents the results of the research, the aim of which was to examine the attitudes and opinions of teachers about the implementation of the preventive system and how it affects the discipline of students at the Salesian Elementary School in Zagreb. Two teachers who work in an extended stay at the Salesian Elementary School in Zagreb were interviewed. The data was collected using the interview method, that is, a semi-structured interview with pre-determined questions, but also the possibility of minor deviations from the given topic. The results of this research showed that the teachers have a similar explanation of the concept of discipline, use similar disciplining techniques in situations where students need to be appeased, and believe that punishments do not have a good effect on student discipline and education in general. The results show that students raised in the preventive system have a well-developed sense of the needs of others and respect for set boundaries. The research came to the conclusion that the methods of the preventive system have a positive effect on students' discipline in the Salesian Elementary School in Zagreb.