Background: Recent global increases in medical student numbers and shifts in medical education from teaching hospitals to community settings call for effective strategies to meet the demand for general practice teaching placements. It has been proposed that "multi-level learning" (MLL), in which learning and teaching are shared across different levels of learners, may provide teaching efficiencies and valuable experiences for learners and teachers. Aims: To identify, evaluate and synthesize the evidence related to the types, benefits, challenges, and facilitators of MLL in community-based general practice, and the underlying mechanisms and associated contexts to explain the reported outcomes. Method: A realist synthesis approach guided the systematic review. Results: Fifteen papers were identified, providing primary evaluation data predominantly from interviews with or surveys of key stakeholders. Generally, all levels of learners reported overall satisfaction with their MLL experiences. Medical students appreciated learning from prevocational doctors and registrars due to social and cognitive congruence. Mechanisms and contexts that supported our hypotheses regarding successful MLL outcomes were identified, with "a strong teaching culture" being a major mechanism. Conclusions: The findings can help inform practices considering the implementation or enhancement of MLL initiatives in general practice. Further research should include measuring defined learning outcomes.