The aim of the present research is to identify whether teachers' attitudes towards the use of Content and Language Integrated Learning (CLIL) in the Republic of Kazakhstan can undergo significant changes if they study a course introducing them to the fundamentals of CLIL. Despite the country's plans to adopt English as one of the languages of education, stakeholders' attitudes towards teaching through the medium of this language remain rather skeptical. A survey was held among Master's degree students majoring in Education (n = 59) at Pavlodar State University before the course and after its completion. Since it is the affective component that largely determines the quality of attitudes, the levels of participants' anxiety, self-esteem and motivation were used as the indicators. The tools for measuring these variables were the State-Trait Anxiety Inventory, Dembo-Rubinstein's Method of Self-esteem Measurement and Dubovitskaya's Diagnostics of Learning Motivation Orientation. The end-of-course results show a marked reduction in the level of participants' state anxiety, a growth in self-esteem in terms of the readiness to use CLIL,and a shift towards intrinsic motivation. It is argued that for attitudes shift to take place, it is necessary to adopt a constructivist approach to teaching and learning.