Aim: To provide depth and breadth in the analysis of nursing students' written narratives of 'most memorable' professionalism dilemmas. Background: While nursing students are taught professionalism through formal curricula, they commonly experience workplace-based professionalism dilemmas. Although non-UK studies have begun to explore students' lived experiences of dilemmas, they lack detail about when and where dilemmas occur, who is involved, what students do and why and how students feel. Design: Online survey of healthcare students including 294 nursing students from 15 UK nursing schools. Method: Nursing students provided a written narrative of their most memorable dilemma (December 2011-March 2012) as part of a survey examining the impact of professionalism dilemmas on moral distress. We conducted thematic and discourse analysis of all narratives and narrative analysis of one exemplar. Findings: The most common themes were patient care dilemmas by healthcare personnel or students, student abuse and consent dilemmas. Of the dilemmas, 49·6% occurred over 6 months previously, 76·2% occurred in hospitals and 51·9% of perpetrators were nurses. 79·3% of students reported acting in the face of their dilemma. Of the narratives, 88·4% contained negative emotion talk and numerous significant relationships existed between types of emotion talk and dilemmas. Our narrative analysis demonstrates the impact of dilemma experiences through emotion talk and more subtle devices like metaphor. Conclusion: Findings extend previous research with nursing and medical students. Nurse educators should help students construct emotionally coherent narratives to make sense of their experiences, actions and identities and to better prepare them for future professionalism dilemmas. © 2014 John Wiley & Sons Ltd.