Background: Communication is central to implementing palliative care (PC) and effective interdisciplinary team functioning. Communication about existential issues is often urgent in PC, yet interdisciplinary teams frequently lack the time and education to meet these communication needs. Thus, more knowledge of existential conversations in different PC contexts is required. Aim: This study aimed to gain an in-depth understanding of healthcare professionals’ (HCPs) experiences of existential conversations with patients with PC needs and their next-of-kin by generating a theoretical model. Method: Seven focus-group interviews that included 26 HCPs who worked with PC patients in different care settings were carried out in 2020 and 2022. The grounded theory method was used to analyse and compare data from the interview transcripts. Results: The HCPs’ primary concern in daily work was establishing a trusting relationship, a prerequisite for enabling existential conversations with a person with PC needs and/or their next-of-kin. The main concern was characterised by the core category maintaining presence and four categories describing interdisciplinary strategies that the HCPs used to achieve a trusting relationship and enable existential conversations in the late phase of life. Several potential barriers also hindered existential conversations. The theoretical model ‘meaningful existential conversations in PC’ was constructed. Conclusions: The interdisciplinary strategies used to establish existential conversations, the potential barriers to these conversations and the model we present can be used as a basis for reflection in professional collaborative learning in PC, as a tool for teachers in educational PC programmes and as a guide for HCPs in PC.