Gaining insight into contextual factors and mechanisms supporting or hindering autonomy supportive consultation and into outcomes of such consultations.We conducted a systematic review using the realist synthesis procedure according to RAMESES guideline. A search was performed in PubMed, Embase, PsycINFO and Cinahl from inception to March 2019 using the search terms: 'autonomy' AND 'support' AND 'consultation' OR 'communication' AND 'intervention'. The review process including paper selection, quality assessment, full text reading for data-extraction was conducted by two researchers independently.Of 2792 articles, 18 met our inclusion criteria. Contextual factors influencing an autonomy supportive consultation were: work organization and the attitude of professionals. An overarching supporting mechanism for AS was relationship building. In addition, each phase of the decision-making process seems to need supporting mechanisms fulfilling patients 'specific psychological needs in that phase. The outcome of AS is higher levels of patient well-being.Autonomy supportive consultation works under various contexts coupled with mechanisms that give rise to favourable-outcomes, of which relationship building, taking time and exploring patients' needs seem the most important.The results of our review facilitate professionals to reflect on their autonomy supportive consultation skills, which could improve their autonomy supportive behaviour.