Background: Older adults hospitalized following a fall often encounter preventable adverse events when transitioning from hospital to home. Discharge planning interventions developed to prevent these events do not all produce the expected effects to the same extent. This realist synthesis aimed to better understand when, where, for whom, why and how the components of these interventions produce positive outcomes. Methods: Nine indexed databases were searched to identify scientific papers and grey literature on discharge planning interventions for older adults (65+) hospitalized following a fall. Manual searches were also conducted. Documents were selected based on relevance and rigor. Two reviewers extracted and compiled data regarding intervention components, contextual factors, underlying mechanisms and positive outcomes. Preliminary theories were then formulated based on an iterative synthesis process. Results: Twenty-one documents were included in the synthesis. Four Intervention-Context-Mechanism-Outcome configurations were developed as preliminary theories, based on the following intervention components: 1) Increase two-way communication between healthcare providers and patients/caregivers using a family-centered approach; 2) Foster interprofessional communication within and across healthcare settings through both standardized and unofficial information exchange; 3) Provide patients/caregivers with individually tailored fall prevention education; and 4) Designate a coordinator to manage discharge planning. These components should be implemented from patient admission to return home and be supported at the organizational level (contexts) to trigger knowledge, understanding and trust of patients/caregivers, adjusted expectations, reduced family stress, and sustained engagement of families and professionals (mechanisms). These optimal conditions improve patient satisfaction, recovery, functional status and continuity of care, and reduce hospital readmissions and fall risk (outcomes). Conclusions: Since transitions are critical points with potential communication gaps, coordinated interventions are vital to support a safe return home for older adults hospitalized following a fall. Considering the organizational challenges, simple tools such as pictograms and drawings, combined with computer-based communication channels, may optimize discharge interventions based on frail patients’ needs, habits and values. Empirically testing our preliminary theories will help to develop effective interventions throughout the continuum of transitional care to enhance patients’ health and reduce the economic burden of avoidable care.