Context: The goal of advance care planning (ACP) is to help ensure that the care people receive during periods of serious illness is consistent with their preferences and values. There is a lack of clear understanding about how patients and their informal carers feel ACP discussions should be implemented. Objectives: The objective of this study was to synthesize literature reviews pertaining to patients' and informal carers' perspectives on ACP discussions. Methods: This is a systematic review of reviews. Results: We identified 55 literature reviews published between 2007 and 2018. ACP discussions were facilitated by a diverse range of formats and tools, all of which were acceptable to patients and carers. Patients and carers preferred health professionals to initiate discussions, with the relationships they had with the professionals being particularly important. There were mixed feelings about the best timing, with many people preferring to defer discussions until they perceived them to be clinically relevant. ACP was felt to bring benefits including a greater sense of peace and less worry, but it could also be disruptive and distressing. Patients and carers perceived many benefits from ACP discussions, but these may differ from the dominant narratives about ACP in health policy and may move away from the narratives of RCTs and standardization in research and practice. Conclusion: Researchers and clinicians may need to adjust their approaches as current practices are not aligned enough with patients' and carers' preferences. Future research may need to test implementation strategies of ACP interventions to elucidate how benefits from standardization and flexibility might both be realized.