Modern-day school is faced with various challenges and difficulties that cannot be dealt with without school counsellors. Counselling in schools in one of the key duties of school pedagogues and psychologists which is characterized by immediate communication with students, teachers and parents. Considering the fact that school counselling is a very complex pedagogical function which requires certain competences on part of the counsellor, it is necessary for school counsellors to take part in additional education and one such possibility is training in Choice Theory and Reality Therapy. There is a relatively small number of available studies in the world that deal with the application of Choice Theory in schools and there has not been a single research found in Croatia that studies the application of Choice Theory in school counselling. Therefore, the main objective of this research was to examine experiences of four school counsellors with the application of Choice Theory in the counselling process and to analyze the importance of formal Choice Theory training for their work. This research showed that the internalization of Choice Theory beliefs proved to be of utmost importance for the perceived quality of the counselling process and the feeling of competence amongst school counsellors. Accordingly, it has been noted that the research participants felt greater satisfaction in both their professional and private lives after having started their Choice Theory training, which is particularly manifested in their relationships with other people, both clients and colleagues. What was has also been found is that the participants didn’t have any difficulties with the application of Choice Theory into their counselling work and that they would like to witness the traditional school system’s advancement towards Glasser’s Quality School. Furthermore, the results comparison pointed towards the importance of lifelong learning considering the fact that all of the participants stressed out the necessity of permanent training of school counsellors at the very beginning of the conversation before they were even asked about it. All of the participants would advise school counsellors to seek further education and would recommend Choice Theory as the best option. Considering the fact that this research featured a small amount of participants, the results should be viewed as a stepping stone for further study of Choice Theory in Croatia.