Within science education reforms, a pedagogical shift from a teachercentred, textbook-based instructional paradigm to a studentcentred, inquiry-based model is called for. Despite strong theoretical grounding, there is limited evidence that primary teachers effectively engage students in pedagogical approaches associated with inquirybased science curriculum in classroom settings. This study examines the constraints faced by primary school teachers in practicing inquiry-based environmental studies curricula using multiple case study design. Classroom observations, semi-structured interviews, and focussed group discussions were used for conducting crosssectional thematic analysis of the data. It emerged that owing to accountability pressures, non-synchronisation between curriculum and assessment practices backed by their personal beliefs in lecture method receded inquiry based teaching-learning practices in classrooms. Finally, possibilities for embedding inquiry-based science in classroom practices are explored.