BACKGROUND: Decision-making in palliative care usually involves both patients and family caregivers. However, how concordance and discordance in decision-making manifest and function between patients and family caregivers in palliative care is not well understood. OBJECTIVES: To identify key factors and/or processes which underpin concordance and/or discordance between patients and family caregivers with respect to their preferences for and decisions about palliative care; and ascertain how patients and family caregivers manage discordance in decision-making in palliative care. METHODS: A systematic review and narrative synthesis of original studies published in full between January 2000 and June 2021 was conducted using the following databases: Embase; Medline; CINAHL; AMED; Web of Science; PsycINFO; PsycARTICLES; and Social Sciences Full Text. RESULTS: After full-text review, 39 studies were included in the synthesis. Studies focused primarily on end-of-life care and on patient and family caregiver preferences for patient care. We found that discordance between patients and family caregivers in palliative care can manifest in relational conflict and can result from a lack of awareness of and communication about each other's preferences for care. Patients' advancing illness and impending death together with open dialogue about future care including advance care planning can foster consensus between patients and family caregivers. CONCLUSIONS: Patients and family caregivers in palliative care can accommodate each other's preferences for care. Further research is needed to fully understand how patients and family caregivers move towards consensus in the context of advancing illness.