Introduction: A trusting relationship between medical learners and clinical teachers is vital for educational and clinical productivity. Perceptions of a trusting relationship are influenced by the learner’s perception of the interpersonal risk (i.e. being humiliated) for engaging in learning behaviours (e.g. asking questions, seeking feedback, learning from mistakes). Perceptions of low interpersonal risk are linked to learners feeling comfortable engaging in learning behaviours. What is less clear is how the clinical environment may influence a medical learner’s perception of trust. Methods: Using constructivist grounded theory, we conducted semi-structured interviews with 19 medical clerks and 10 clinical educators affiliated with a single institution. Interviews explored participants’ personal experiences of positive, negative or challenging learner-teacher relationships in the clinical environment. Results: Through qualitative analysis, we developed a theory of Co-Navigation which describes how teachers and learners have common points of interaction to solidify or diminish trust as they navigate the dynamics of the clinical environment. These points in the relationship that each must co-navigate include: preparing to work together; asking questions; engaging in clinical work; and addressing learner mistakes. Perceptions of whether the opportunity solidified or dissolved trust, arose from learners’ perception of the amount of effort their teacher made to mitigate stress learners experienced in the learning environment. Limitations: Our interview participants were recruited as individuals; we did not examine their perceptions of their relationships with each other. Co-recruitment of teacher-learner dyads may be a strategy to further refine this theory in future research. Conclusion: The Co-Navigation theory helps teachers and learners identify key opportunities in the relationship and suggests approaches to solidifying trust at these critical junctures. It highlights the role the clinical environment plays in facilitating and constraining opportunities to establish trust. / Thesis / Master of Health Sciences (MSc) / This thesis project aimed to understand how the clinical environment shapes the way medical learners interact and build relationships with their clinical teachers. We interviewed medical students and clinical teachers who worked together during the medical learner’s clerkship year of clinical training in various healthcare specialties. In the interviews, we discussed learner experiences of positive and negative relationships with clinical teachers. We developed a theory which describes four opportunities that medical learners and clinical teachers will encounter that can support the development of a trusting relationship. This thesis project will contribute insight into types of interactions that can be highlighted as strategic points for educational interventions and administrative reform, to support the development of trusting learner-teacher relationships during clerkship.