Structured thinking activities (STAs) are pedagogical tools used to support metacognition in classrooms. Despite their popularity, little is known about how pupils use STAs as platforms to think about and manage their own thinking (i.e. as metacognitive tools). This case study investigated pupils' use of STAs in relation to metacognition throughout a school year. We focus on two 8-year-old pupils, Amy and Laura, as they completed two specific STAs through weekly class meets and termly achievement logs. Data were triangulated through participant observation, qualitative interviews and analysis of written texts. We found clear differences between Laura's and Amy's written STAs, however observation and interviews revealed that engagement with STAs was similar beyond that suggested by the written evidence alone. Whereas Amy used easily spelt 'stock' responses, Laura used 'bare minimum' responses to meet teacher expectations. As such, neither Amy nor Laura used STAs as metacognitive tools, however in negotiating STAs, both exhibited strategic regulatory skills indicative of metacognition. Whilst our findings highlight that pupils may still be developing explicit metacognitive knowledge necessary to take full advantage of STAs, we highlight the clear value of persistent approaches to using STAs as tools to support developing metacognition, particularly in association with teacher--pupil interactions.