Aim: To explore nursing students’ experiences of encountering patients’ existential concerns during clinical placements. Background: Existential concerns about the purpose of life, illness, and death are integral to human experience, and are common in healthcare. Illness disrupts life, intensifying these concerns and leaving patients in need of support. Nursing students often encounter these concerns during clinical placements, but their experiences in clinical settings are sparsely studied. Methods: Eleven second-year nursing students from a Swedish university participated in lifeworld interviews during clinical placements. These interviews were transcribed verbatim and analysed using reflective lifeworld research. Results: Encountering patients’ existential concerns is described as a process of becoming a nurse through uncertainty and shared experiences with patients. Encountering patients’ existential concerns is a transformative and emotional process. Despite theoretical preparation, these uncertain situations represent a challenge, as the tension between emotional engagement and clinical demands complicates their responses. These patient interactions foster compassion and deepen understanding of life's fragility, underscoring nursing's complexity—balancing competence with emotional presence. Encountering patients’ existential concerns is essential for students’ learning. This is further elaborated on in four constituents. Conclusions: Encountering patients’ existential concerns challenges students but creates personal and professional growth. Nursing students engage deeply in care, experiencing compassion that can evoke feelings of hopelessness and anxiety. They need educational support and preceptors’ guidance to reflect on these emotional encounters. Integrating existential reflection, self-compassion, and structured support helps them become professional and compassionate nurses.