The traineeship of educators is a period full of challenges and changes aimed at developing personality and professional development. The theoretical part provides an overview of the profession, the professional identity of educators, trainee educators, stages and aspects of internships, the relationship between trainee educators and mentors, as well as the stages of their relationship. Also, the paper will present the professional development of trainee educators, lifelong learning and the legal framework of internships. Within the theoretical part, it is concluded that the internship in the educational profession belongs to lifelong learning, one of the most important parts. The aim of the research was to show that there is a need to change the organization of the internship, and the emphasis is on the professional development of trainee educators. The study involved 110 respondents, of which 59 trainee educators and 51 educators who passed the professional exam. In the diploma thesis, 5 research questions were asked with the aim of better understanding the professional development of trainee educators. The results of the research indicate the need to revise the Ordinance on the manner and conditions of taking the professional exam for educators and professional associates in kindergarten from 1997. Changes were observed in the mentor's modern methodological approach to trainees. Achieving quality guidance and preparation of trainees, it is necessary to enable a larger number of professional gatherings for trainees. The results of the research show that the city in which the internship influences the professional development of trainee educators. Following the theoretical framework and the obtained results, it can be concluded that a change in the organization of the internship is needed in order to acquire and strengthen the competencies of trainee educators.