Teaching through the integration and correlation of teaching contents and subjects involves selecting, applying and adapting the teaching methods to the pupils' needs, abilities and interests, to ensure educational success, but also to encourage the development of all areas of the student's personality. In the context of this, it is necessary to implement collaborative learning strategies in teaching because they encourage students to work and develop critical and creative thinking, communication and social skills, and strengthen self-esteem. The aim of this study was to examine the use of collaborative learning that teachers implement in teaching, the frequency of use of collaborative work strategies within teaching subjects, as well as integrated teaching, with examples of good practice of lectures preparation. Significance has also been attributed to the limiting factors that teachers emphasize in the use of collaborative strategies. In the research, through the questionnaire, participated teachers (N = 115) in three counties (Primorsko-goranska, Istra and Karlovac). We have found that the use of collaborative learning in teaching is insufficient, and that there is a very diverse representation of it in certain subjects. It has been shown by teacher attitudes that the use of collaborative strategies is most influenced by positive interpersonal relationships and positive classroom environments. Among the limiting factors for the use of collaborative strategies, teachers most often distinguish the number of pupils in the classroom and the expected time to complete the activities. The most commonly used form of integrated teaching is the correlation and the most commonly implemented themes in the integrated form of teaching are the seasons and the occasional themes. The orientation towards modern teaching, in accordance with the national framework curriculum, opens the door to the introduction of integrated teaching in the educational practice with the use of different forms and methods of teaching, collaborative strategies in which students with moderation of the teachers discover the knowledge on their own and with cooperation systematize it.