Nowadays teachers are being prepared to work exclusively in classical, so-called pure classes. Working in the combined classes is mentioned only occasionally. That is why there is a problem when young teachers get their first job in a combined department. Combined classes are formed mostly in rural areas where there is not enough pupils for pure classes. For that reason, a department of two, three or four classes is led by one teacher. The aim of this paper was to describe the specifics of working in a combined class, based on the principles of constructivist didactics. Constructivist didactics implies the activity and autonomy of the student who builds his own knowledge based on experience and critically reflects on what he is learning. Constructivist teaching is opposed to the traditional lecturer-oriented teaching, which turns the student into a passive object. In this paper, the aim of the research was to demonstrate the implementation of constructivist principles in the combined class. The research was conducted in a small regional school in Grabovnica with students of the second and fourth class combination. It was concluded that teaching in combined departments because of their specificity (alteration of direct and indirect forms of work) requires the implementation of constructivist principles. In combined classes, teaching must be dynamic, we must encourage the activity of each student and their mutual cooperation. All of this implies a lot of preparation for a teacher who takes on the role of organizer and mentor. In this way we encourage the interest and activity of the students who do not take the school as a place where they have to listen to the teacher and remember the facts in order to reproduce them later.