Encouraging and developing students' critical thinking is the aim of the modern educational process. Critical thinking is a competence that needs to be encouraged and developed in students from the earliest school age. Teachers who understand the purpose and task of encouraging and developing critical thinking of younger school-age students will more easily and better encourage and develop critical thinking of their students. This tells us that teacher competencies are very important for encouraging and developing students' critical thinking. Students who know how to think critically and draw conclusions independently and argumentatively find it easier to cope with the process of learning and collaborating with others. The thesis discuss Encouraging critical thinking in the Croatian language class in the younger grades of primary school sought to examine whether primary school teachers encourage critical thinking of younger school-age students in Croatian language teaching, which teaching strategies they use, and whether they are considered competent enough to encourage and develop critical thinking opinions of younger school students. In this masters thesis, textbooks from the first to the fourth grade are analyzed, thus tasks in textbooks aimed at encouraging critical thinking of students. The analysis revealed that such tasks exist in textbooks, and this is confirmed by the respondents who were asked a question related to the tasks in textbooks. The research was conducted on a sample of 170 respondents, using a quantitative survey method. The results of the research showed that primary school teachers encourage critical thinking of younger school-age students in the teaching of the Croatian language, most often in the literature and creativity class. It is laudably and positive that there are respondents who state that critical thinking in the teaching of the Croatian language is encouraged in almost every lesson of the Croatian language. Such respondents are still in the minority. Classroom teachers use a variety of teaching strategies to encourage critical thinking. A very positive fact is that more than half of the respondents are generally considered competent to encourage critical thinking of students and more than half of the respondents participate in professional development to acquire additional knowledge and skills and thus more easily encourage and develop important life competencies of students.