Objectives Although previous studies have explored medical learners''most memorable' experiences, these have typically focused on patient deaths or mistakes. Drawing on multiple theoretical perspectives to understand the interplay between narrative, emotion and action, this paper aims to explore the whats and hows of written narratives of most memorable professionalism dilemmas: what types of dilemma are most memorable? When and where do they take place? How do students act? What characteristics relate to these dilemmas? How are dilemmas narrated? Methods A total of 680 students from 29 of 32 UK medical schools provided a written narrative of their most memorable dilemma as part of their responses to an online questionnaire exploring the impact of professionalism dilemmas on moral distress. We employed quantitative thematic and discourse analysis of all narratives using Linguistic Inquiry Word Count software (liwc) and conducted a narrative analysis of one exemplar. Results The most common themes across all narratives concerned dilemmas that related to issues of patient care with reference to the actions of health care professionals or students, student abuse, and consent and intimate examination. A total of 41.1% of experiences had occurred over 6months previously and 80.1% had taken place in hospital settings. Overall, 54.9% of narrators reported having done something in the face of their dilemma, although only 13.2% described taking obvious or direct action. Numerous characteristics were related to most memorable dilemmas (e.g. narratives citing intimate examinations were more likely to take place in surgical settings). A total of 92.6% of narratives included negative emotion talk and numerous significant relationships emerged between types of emotion talk and most memorable dilemmas (e.g. more anger talk in abuse narratives). Our narrative analysis of one exemplar illustrates the richness of emotion talk and more subtle devices to establish emotional tone. DISCUSSION Findings extend previous research into issues related to professionalism by exploring relationships between narrative, emotion and action in the context of written narratives of most memorable dilemmas. We encourage medical educators to help students construct coherent and emotionally integrated narratives to make sense of negative professionalism dilemmas.