Combined classroom departments, usually organized in district schools, form an important part of education in Croatia. Lessons organized in combined classroom departments are complex, unique and dynamic, as well as teaching Science. The aim of the research was to determine specificities of teaching Science in combined classroom department and to warn the teachers on difficulties and advantages of teaching Science in already mentioned departments. Twenty examinees participated in the research, all of them the teachers of combined classroom departments. All examinees are from Krapinsko-zagorska and Varaždinska Country. The purpose of the research is to provide an insight in teaching Science in combined classroom departments to the teachers of combined departments, as well as to the teachers of regular classes and the students, future teachers. Furthermore, the teachers will gain the basic information about a way of planning and organizing the lesson in mentioned departments. The results showed that teaching Science in combined classroom departments is not problematic. On the contrary, it provides more freedom and creativity to the teachers and it ensures a level of independence and tolerance to the students, which is hard to achieve in regular classrooms. Moreover, students of combined departments are more successful in achieving aims and outcomes of both lessons and outdoor school. The students also conduct many projects all together. With this paper, with direct experience of the teachers, beliefs and attitudes towards combined classroom departments could be changed.