Background: It is often suggested that terminally ill patients favour end-of-life care at home. Yet, it is unclear how these preferences are formed, if the process is similar for patients and carers, and if there are discrepancies between preferences for place of care and place of death. Understanding these nuances is essential to support people in their decision-making and ultimately provide better care at the end of life. Aim: To gain an in-depth understanding of how terminally ill patients and their family caregivers make decisions about preferred place of care and place of death. Design: Semi-structured interviews with patients and carers, which were analysed thematically using qualitative description. Setting/ participants: A total of 17 participants (eight patients and nine carers) recruited from an acute palliative care hospital ward, a sub-acute hospice unit, and a palliative homecare organisation in Melbourne, Australia. Results: The process of forming preferences for place of care and place of death was shaped by uncertainty relating to the illness, the carer and the services. Participants dealt with this uncertainty on a level of thoughts, emotions, and actions. At the end of this process, participants expressed their choices as conditional, personal, relational, contextual and flexible preferences. Conclusions: End-of-life decision-making rarely ends with a clear and stable choice. Understanding the reasons for the malleability of preferences and the process of how they are formed has implications for both clinicians and researchers.