jats:sec <jats:title content-type="abstract-subheading">Purpose</jats:title> jats:pThe purpose of this paper is to provide an analysis of processes in operation during the implementation of a reform programme in Kazakhstan culminating in the widespread adoption of Lesson Study (LS).</jats:p> </jats:sec> jats:sec <jats:title content-type="abstract-subheading">Design/methodology/approach</jats:title> jats:pThe study is positioned within a critical realist theoretical perspective, drawing on Archer’s social theory to focus on the social world of the school while changes to classroom practice are being made. This is a case study using process tracing methods to analyse how school actions and interactions are used during the change process resulting in widespread implementation of LS.</jats:p> </jats:sec> jats:sec <jats:title content-type="abstract-subheading">Findings</jats:title> jats:pThree key mechanisms for implementing the structural changes are identified; increasing teacher’s pedagogical knowledge, collaborative working structures and active collective inquiry. The capacity to change practice is underpinned by reflection on classroom interactions and in having the necessary skills and available time to analyse the effect on pupils’ learning. Engaging in reflexive deliberation is dependent on having access to new knowledge, together with the opportunity to collaborate in supportive groups.</jats:p> </jats:sec> jats:sec <jats:title content-type="abstract-subheading">Originality/value</jats:title> jats:pThis study provides an insight into what changes were made and why these support the spread of LS in Kazakhstan, drawing on Archer’s social theory and using theory building process tracing methods to delve deeper into the empirical fingerprints left during the intervention. LS is an important structural factor which is still supporting change in Kazakhstani classrooms.</jats:p> </jats:sec>