Purpose To explore how medical teachers navigate their professional identities when required to implement critical pedagogy during an undergraduate curriculum renewal initiative. Methods A qualitative exploratory study was conducted, using focus groups and individual interviews with twenty-six purposively selected undergraduate medical teachers at a South African university. Data were transcribed, coded, and thematically analysed. Concepts of Landscapes of Practice Theory and Teacher Identity Learning provided an interpretive framework. Results Findings show that medical teachers’ perceived capacity to implement critical pedagogy was influenced by identities that were constructed within the boundaries of a traditional biomedical curriculum. Three themes were identified, highlighting the inherent liminality of traversing a changing educational landscape: engaging in new practices: moving into the boundary space; attempting alignment: navigating identity in the boundary space; imagining the future: embracing identity in the boundary space. Conclusion Globally directed curriculum renewal imperatives may challenge the established pedagogical practices and professional identities of medical teachers. There is a need for institutional spaces that foster collaboration, dialogue, and reflection with a view to supporting the ongoing identity learning and development of knowledgeability of medical teachers responsible for curriculum transformation.