AbstractBackgroundNumbers of street‐connected children and young people run into many millions worldwide and include children and young people who live or work in street environments. Whether or not they remain connected to their families of origin, and despite many strengths and resiliencies, they are vulnerable to a range of risks and are excluded from mainstream social structures and opportunities.ObjectivesTo summarise the effectiveness of interventions for street‐connected children and young people that promote inclusion and reintegration and reduce harms. To explore the processes of successful intervention and models of change in this area, and to understand how intervention effectiveness may vary in different contexts.Search methodsWe searched the following bibliographic databases, from inception to 2012, and various relevant non‐governmental and organisational websites: Cochrane Central Register of Controlled Trials (CENTRAL); MEDLINE and PreMEDLINE; EMBASE and EMBASE Classic; CINAHL; PsycINFO; ERIC; Sociological Abstracts; Social Services Abstracts; Social Work Abstracts; Healthstar; LILACS; System for Grey literature in Europe (OpenGrey); ProQuest Dissertations and Theses; EconLit; IDEAS Economics and Finance Research; JOLIS Library Catalog of the holdings of the World Bank Group and IMF Libraries; BLDS (British Library for Development Studies); Google, Google Scholar.Selection criteriaThe review included data from harm reduction or reintegration promotion intervention studies that used a comparison group study design and were all randomised or quasi‐randomised studies. Studies were included if they evaluated interventions aimed to benefit street‐connected children and young people, aged 0 to 24 years, in all contexts.Data collection and analysisTwo review authors independently extracted data and assessed the risk of bias of included studies. Data were extracted on intervention delivery, context, process factors, equity and outcomes. Outcome measures were grouped according to whether they measured psychosocial outcomes, risky sexual behaviours or substance use. A meta‐analysis was conducted for some outcomes though it was not possible for all due to differences in measurements between studies. Other outcomes were evaluated narratively.Main resultsWe included 11 studies evaluating 12 interventions from high income countries. We did not find any sufficiently robust evaluations conducted in low and middle income countries (LMICs) despite the existence of many relevant programmes. Study quality overall was low to moderate and there was great variation in the measurement used by studies, making comparison difficult. Participants were drop‐in and shelter based. We found no consistent results on a range of relevant outcomes within domains of psychosocial health, substance misuse and sexual risky behaviours despite the many measurements collected in the studies. The interventions being evaluated consisted of time limited therapeutically based programmes which did not prove more effective than standard shelter or drop‐in services for most outcomes and in most studies. There were favourable changes from baseline in outcomes for most particpants in therapy interventions and also in standard services. There was considerable heterogeneity between studies and equity data were inconsistently reported. No study measured the primary outcome of reintegration or reported on adverse effects. The review discussion section included consideration of the relevance of the findings for LMIC settings.Authors' conclusionsAnalysis across the included studies found no consistently significant benefit for the ‘new’ interventions compared to standard services for street‐connected children and young people. These latter interventions, however, have not been rigorously evaluated, especially in the context of LMICs. Robustly evaluating the interventions would enable better recommendations to be made for service delivery. There is a need for future research in LMICs that includes children who are on the streets due to urbanisation, war or migration and who may be vulnerable to risks such as trafficking.Plain Language SummaryInterventions for reducing risks and promoting inclusion of street children and young peopleThere are millions of children and young people estimated to be living and working on the streets around the world. Many have become resilient but continue to be vulnerable to risks. To promote their best chances in life, services are needed to reduce risks and prevent marginalisation from mainstream society. Eleven studies evaluating 12 interventions have been rigorously conducted of services to support street‐connected children and youth, all in the developed world. They compared therapy‐based services with usual shelter and drop‐in services. The results of these studies were mixed but overall we found that participants receiving therapy or usual services benefitted to a similar level. There is a need for research which considers the benefit of usual drop‐in and shelter services, most particularly in low and middle income countries, and which includes participation of street‐connected children and young people. None of the studies included participants that were comparable to some street children in low income countries, who may be on the street primarily to earn a living or as a result of war, migration or urbanisation.