Purpose: This study explores one-to-one LEGO® Serious Play® in positive psychology coaching (1-1 LSP in PPC) as an intervention to help emerging adults (EAs) in higher education develop a growth mindset. Design/methodology/approach: This is a qualitative single-participant case study of an EA undergraduate student's experience with 1-1 LSP in PPC to help him navigate uncertainty about making a decision that he felt would influence his future career. Findings: 1-1 LSP in PPC enabled the participant to create a metaphoric representation of how a growth mindset operated for him, promoting self-awareness and reflectivity. The LEGO® model that the participant built during his final session acted as a reminder of the resources and processes he developed during coaching, which helped him navigate future challenges. Research limitations/implications: This study contributes to the emerging literature on the impact of using LSP as a tool in one-to-one coaching in higher education. The participant's experience demonstrates that 1-1 LSP in PPC may be an effective way to support positive EA development. More research is needed to explore its potential. Practical implications: This study provides a possible roadmap to incorporate 1-1 LSP in PPC into coaching in higher education as a reflective tool to build a growth mindset in EA students. Originality/value: Because most undergraduates are EAs navigating the transition from adolescence into adulthood, universities would benefit from adopting developmentally informed coaching practices. 1-1 LSP in PPC may be an effective intervention that provides the structured and psychologically safe environment EAs need to develop lasting personal resources.