BackgroundEngagement in healthcare decision making has been recognized as an important, and often lacking, aspect of care, especially in the care of older adults who are major users of the healthcare system.ObjectiveWe aimed to conduct a review of available knowledge on engagement in healthcare decision making with a focus on older patients and their caregivers.MethodsWe conducted a realist synthesis focusing on strategies for engagement of older patients and their caregivers in healthcare decision making. The synthesis encompassed theoretical frameworks and both peer-reviewed and grey literature. Expert consultations included interviews (n = 2) with academics and group consultations (n = 3) with older adults and their caregivers. Abstracts that reported description, assessment, or evaluation of strategies for engagement of adult patients, families, or caregivers (i.e., that report on actual experiences of engagement) were included.ResultsThe search generated 15,683 articles, 663 of which were pertinent to healthcare decision making. Theoretical and empirical work identified a range of strategies and levels of engagement of older patients and their families in healthcare decision making. The importance of communication emerged as a key recommendation for meaningful engagement among providers and patients and their caregivers. The principles developed in this study should be implemented with consideration of the context in which care is being provided.ConclusionsWe have developed a framework that promotes the engagement of patients and their caregivers as equal partners in healthcare decision making. Future research should implement and test the framework in various clinical settings.Electronic supplementary materialThe online version of this article (doi:10.1007/s40271-016-0168-x) contains supplementary material, which is available to authorized users.