Background: An upstream approach to palliative care in the last 12 months of life delivered by primary care practices is often referred to as Primary Palliative Care (PPC). Implementing case management functions can support delivery of PPC and help patients and their families navigate health, social and fiscal environments that become more complex at end-of-life. A realist synthesis was conducted to understand how multi-level contexts affect case management functions related to initiating end-of-life conversations, assessing patient and caregiver needs, and patient/family centred planning in primary care practices to improve outcomes. The synthesis also explored how these functions aligned with critical community resources identified by patients/families dealing with end-of-life. Methods: A realist synthesis is theory driven and iterative, involving the investigation of proposed program theories of how particular contexts catalyze mechanisms (program resources and individual reactions to resources) to generate improved outcomes. To assess whether program theories were supported and plausible, two librarian-assisted and several researcher-initiated purposive searches of the literature were conducted, then extracted data were analyzed and synthesized. To assess relevancy, health system partners and family advisors informed the review process. Results: Twenty-eight articles were identified as being relevant and evidence was consolidated into two final program theories: 1) Making end-of-life discussions comfortable, and 2) Creating plans that reflect needs and values. Theories were explored in depth to assess the effect of multi-level contexts on primary care practices implementing tools or frameworks, strategies for improving end-of-life communications, or facilitators that could improve advance care planning by primary care practitioners. Conclusions: Primary care practitioners’ use of tools to assess patients/families’ needs facilitated discussions and planning for end-of-life issues without specifically discussing death. Also, receiving training on how to better communicate increased practitioner confidence for initiating end-of-life discussions. Practitioner attitudes toward death and prior education or training in end-of-life care affected their ability to initiate end-of-life conversations and plan with patients/families. Recognizing and seizing opportunities when patients are aware of the need to plan for their end-of-life care, such as in contexts when patients experience transitions can increase readiness for end-of-life discussions and planning. Ultimately conversations and planning can improve patients/families’ outcomes.