This study reports on the impact of a 2-month classroom intervention that sought to alter the learning environment of two Hong Kong Primary Year 3 general studies classrooms. Mixed methodology, employing quantitative and qualitative data-gathering strategies, was used to investigate changes to the learning environments, including changes to the teachers' language and ultimately the students' metacognition. The quantitative facet of the research involved the development of a 15-item learning environments instrument, the General Studies Metacognitive Orientation Scale (GSMOS), that evaluated elements of the metacognitive orientation of the classrooms' learning environments. While the data from the administration of the GSMOS suggested no statistical differences between the pre- and post-intervention environments of the classrooms, student interviews and classroom observations provided supportive data for some changes, which resulted in students developing metacognitive knowledge of teacher-selected thinking and learning strategies, as well as some awareness and limited control of their use of such strategies in their classrooms.