Background Ariadne Labs’ Serious Illness Care Program (SICP), inclusive of the Serious Illness Conversation Guide (SICG), has been adapted for use in a variety of settings and among diverse population groups. Explicating the core elements of serious illness conversations could support the inclusion or exclusion of certain components in future iterations of the programme and the guide.

Aim This integrative systematic review aimed to identify and describe core elements of serious illness conversations in relation to the SICP and/or SICG.

Design Literature published between 1 January 2014 and 20 March 2023 was searched in MEDLINE, PsycINFO, CINAHL and PubMed. All articles were evaluated using the Joanna Briggs Institute Critical Appraisal Guidelines. Data were analysed with thematic synthesis.

Results A total of 64 articles met the inclusion criteria. Three themes were revealed: (1) serious illness conversations serve different functions that are reflected in how they are conveyed; (2) serious illness conversations endeavour to discover what matters to patients and (3) serious illness conversations seek to align what patients want in their life and care.

Conclusions Core elements of serious illness conversations included explicating the intention, framing, expectations and directions for the conversation. This encompassed discussing current and possible trajectories with a view towards uncovering matters of importance to the patient as a person. Preferences and priorities could be used to inform future preparation and recommendations. Serious illness conversation elements could be adapted and altered depending on the intended purpose of the conversation.