Effective mental health care is dependent on engaging service users, but some individuals do not actively attend appointments, and may stop engaging with mental health services. Quantitative studies reveal some salient factors that seem to predict engagement but these studies miss the nuances of good clinical practice in this area. A number of qualitative studies of health professionals' experiences and understanding of effective engagement have been published.This review aimed to systematically identify, evaluate and synthesise results from these studies with a view to informing effective practice in this area.Electronic databases Medline, EMBASE, CINAHL, PsychINFO and AMED were searched (PROSPERO systematic review protocol registry (www.crd.york.ac.uk/prospero/; ID CRD42017083976). Of 799 records, ten papers met the inclusion criteria. All papers were subjected to quality appraisal based on the CASP checklist and data systematically extracted. A thematic synthesis of included studies examining mental health practitioners' experiences of engagement in community mental health settings was conducted.Mental health practitioners see engaging service users as depending upon complex, multi-dimensional phenomena which should include individualised person-centred approaches as well as practical, social and clinical support. Mental health practitioners demonstrate qualities such as determination and adaptability to establish and maintain engagement with service users.As a core aspect of nurse education, registered mental health nurses and other professionals would benefit from systematic guidance regarding engagement strategies. Most studies in this review focused on assertive outreach or community mental health teams, more clarification is needed of practitioner's engagement experiences in early intervention settings.