Objective: Gaining insight into contextual factors and mechanisms supporting or hindering autonomy supportive consultation and into outcomes of such consultations. Methods: 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. Results: 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. Conclusion: 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. Practice implications: The results of our review facilitate professionals to reflect on their autonomy supportive consultation skills, which could improve their autonomy supportive behaviour.