This review sets out to examine the published literature, exploring ways in which contact opportunities associated with cash transfers might help to identify vulnerable households and link them with social welfare services. Social welfare is a very broad construct, ranging from formalized social work provision to an array of service-type encounters, which could fall under the wide umbrella of social welfare, legal provision, family support services, child protective services and alternative care. A systematic review of published papers on cash transfer and social welfare generated 146 studies that were hand-sorted according to a series of inclusion criteria. These required availability of data, design competence and presence of a control group, from low/middle-income countries, cash transfers rather than other transfer types, accessible in the published literature in English reporting on developmental transfers as opposed to emergency transfers. Geographic and provision criteria were reached by 37 studies and only 12 of these included empirical data. Nine were evaluation studies, two used secondary analysis of existing data to explore childbearing and one presented a study synthesis. The majority emanated from South America (only one from South Africa). Two of the 12 were non-conditional pensions (Brazil and South Africa). The remainder were conditional transfers. The review showed that there is a lack of clearly identified, well-controlled, systematic studies from which to glean a sound evidence base on social welfare and cash transfer to guide policy. Studies reporting on nutritional status/child growth found positive effects of cash transfers (n = 6). Children benefiting from the programmes were healthier than those who were not enrolled in the programmes. Studies recorded positive effects of cash transfers on migration outcomes, psychological outcomes, preventative health-care participation, some health outcomes and school-related outcomes such as improved attendance, enhanced enrolment, reduced dropout and earlier enrolment. Cash transfers improved household consumption and expenditures (more spent on children's clothing, education and food – better quality food) to benefit children of the household. Programmes decreased or had no impact on fertility in Mexico, Nicaragua and Turkey. There were some increases in Honduras, which may or may not be related to the programme. No evaluations of cash transfer schemes reported on direct social welfare provision, legal and protective service access and provision. Grandparent residence and reductions in child labour were associated with cash transfers. In countries where there is a lack of traditional provision in terms of social work, there is a large gap in the provision of social support in general, including cash transfer schemes. The growing literature has shown the need for integration of social welfare into existing provision – be it the location of social welfare in general practice or the combining of government support through non-governmental organizations (NGOs) and community-based projects. The clear message is that stand-alone provision may, in itself, be a barrier to access. Studies should move beyond access to services to explore the implications of service provision for health and welfare gains. This review of studies shows multiple opportunities within existing cash transfer provision for social welfare contacts.