Very little is known about shared decision making (SDM) in residential aged care, despite world-wide policy and imperatives that encourage resident choice and autonomy. This paper provides a framework synthesis of SDM in residential aged care (RAC) and potential barriers and enablers to implement SDM utilising a theoretical framework of implementation. A review of the literature on SDM in RAC from 2005 to 2016 was undertaken, using MEDLINE (Ovid), CINAHL, PsychINFO and Scopus. The articles were synthesised by utilising an implementation theory framework to better understand what may facilitate or hinder the introduction of SDM. Eighteen studies were identified and analysed to determine barriers and enablers to SDM in RAC from the perspectives of staff, residents and relatives. A workplace culture of person-centred care and judicious use of research evidence are enablers of SDM. There is a potential need for additional resources, such as education for staff and families to enable implementation of SDM. Implementation of any health care intervention, including SDM, relies on many complex factors but these are predominantly related to capacity. Determining current uptake and readiness of RAC organisations, residents and their families to adopt SDM is an essential starting point.