This study examines the teacher professional development system from the students’ functional literacy perspective in Kazakhstan. The relationship between these parameters is established by conducting quantitative analysis of the data from the Programme for International Student Assessment (PISA) in 2018. The multiple regression analysis was performed to determine the impact of indicators of teachers' participation in professional development activities on students’ academic achievement in three core study areas (reading, mathematics and science). This allows to determine the relative importance of teacher professional development in the development of functional literacy of students among other factors related to the teacher. According to the results of the analysis, a direct positive relationship was revealed between the participation of teachers in professional development programs and the results of students in all three areas of the study. This factor predicts students’ academic performance better than the teacher contracts and teacher certification, even after accounting for the students’ socio-economic profile.