The purpose of this study is to understand the central phenomenon of teacher professionalism, identify the perceptions of teacher professionalism and what factors contribute to or inhibit teacher professionalism. The main research question of this study is how do Nazarbayev Intellectual Schools teachers perceive teacher professionalism in the school? Subsidiary research questions were addressed in order to reach the purpose of the study: what are the teachers' perceptions of the factors that contribute to teacher professionalism at school? and what are their perceptions of the factors that inhibit teacher professionalism? Semi-structured interviews were conducted with ten participants and analyzed with the help of thematic coding and interpretation. The researcher used purposeful sampling. The study is significant because it voices teachers' perceptions of how teacher professionalism is defined in the educational system of independent Kazakhstan as well as in the Central Asia region. The research findings revealed that teacher professionalism in Kazakhstan is a complex notion that comprises various aspects of teaching and learning including commitment to the profession, school-based courses, professional learning communities, and supportive work environment. There are also certain factors that inhibit professionalism including lack of time-management skills, lack of motivation, burnout and paperwork. The study has limitations as only ten participants shared their perspectives on teacher professionalism. Future studies could extend the research by conducting a similar study in other Kazakhstani school contexts, or other schools in Central Asia, to explore other teachers' perceptions regarding professionalism involving teachers of different subjects teaching in rural and urban areas.