ObjectivesLife Story Work (LSW) is used to promote the mental health and well-being of children and adolescents living in out-of-home care. LSW should be offered to all but is conventionally delivered in high-intensity ways. Low-intensity approaches are more accessible but there is significant variation and little guidance for supporting adolescents. We aimed to create guidance for Adolescent-Focused Low-Intensity LSW.DesignRealist review.Data sourcesMEDLINE, Embase, PsycINFO, Sociology Collection (ProQuest), CINAHL, CDAS, Web of Science (SCIE, SSCI), Social Care Online and grey literature sources. Searches were performed between December 2021 and March 2022.Eligibility criteriaDocuments on children and adolescents in care, LSW and/or low-intensity interventions to improve mental health were included. Documents focusing on parenting style and contact with birth family were excluded.AnalysisDocuments were analysed using a realist logic of analysis. In consultation with Content Expert Groups (comprising professionals and care leavers), we developed an initial programme theory. Data relating to and challenging the initial programme theory were extracted and context-mechanism-outcome-configurations developed, critiqued and refined in an iterative fashion. Interpretations were drawn from context-mechanism-outcome-configurations to enhance the programme theory.Results75 documents contributed to the analysis. Generally, studies were small-scale and lacked in-depth methods and evaluation descriptions. Findings indicated important factors contribute to the development of high-quality Adolescent-Focused Low-Intensity LSW. Adolescent-Focused Low-Intensity LSW should be person-centred, begin in the now, involve co-construction, record everyday positive life events and be supported by trained carer(s). Context-mechanism-outcome-configurations relating to these themes are reported.ConclusionsUsing this knowledge we developed initial practice guidance to support social care to deliver better quality Adolescent-Focused Low-Intensity LSW more consistently. To address gaps in our knowledge about the impact of Adolescent-Focused Low-Intensity LSW, further primary research is needed to strengthen understandings of how this intervention works (or not) in different contexts.PROSPERO registration numberCRD42021279816.