AIM: To explore the experiences of undergraduate nursing students regarding hot and cold debriefing styles following Basic Life Support (BLS) training. BACKGROUND: Debriefing plays a vital role in nursing education, especially in simulation-based experiences. Debriefing is defined as a two-directional, "formal, collaborative, reflective process within the simulation learning activity". According to the literature, "hot" debriefings take place within minutes to hours after the simulation, while "cold" debriefings can happen within days to weeks. There is insufficient evidence to determine the most effective debriefing methods for undergraduate nursing students. DESIGN: A qualitative descriptive study was conducted to understand students' perceptions of hot and cold debriefing styles. METHODS: Data were collected through two focus group interviews with 12 undergraduate nursing students. Participants were randomly assigned to hot debriefing (n = 22) or cold debriefing (n = 22), with six students from each group participating in the focus groups. RESULTS: Five main categories emerged from students' perceptions related to simulation and debriefing experiences: Simulation Experience, Debriefing Experience, Reflection, Debriefing Impact on Learning and Feedback for Educators. CONCLUSIONS: It is suggested that incorporating simulation followed by debriefing into the nursing curriculum, particularly for teaching BLS, can be highly beneficial. The study highlights the importance of debriefing in simulation-based education and provides recommendations for enhancing debriefing strategies to enhance nursing skills and knowledge.