Conditional cash transfers (CCT) provide monetary transfers to households on the condition that they comply with some pre‐defined requirements. CCT programmes have been justified on the grounds that demand‐side subsidies are necessary to address inequities in access to health and social services for poor people. In the past decade they have become increasingly popular, particularly in middle income countries in Latin America.

To assess the effectiveness of CCT in improving access to care and health outcomes, in particular for poorer populations in low and middle income countries.

We searched a wide range of international databases, including the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE, in addition to development studies and economic databases. We also searched the websites and online resources of numerous international agencies, organisations and universities to find relevant grey literature. The original searches were conducted between November 2005 and April 2006. An updated search in MEDLINE was carried out in May 2009.

CCT were defined as monetary transfers made to households on the condition that they comply with some pre‐determined requirements in relation to health care. Studies had to include an objective measure of at least one of the following outcomes: health care utilisation, health expenditure, health outcomes or equity outcomes. Eligible study designs were: randomised controlled trial, interrupted time series analysis, or controlled before‐after study of the impact of health financing policies following criteria used by the Cochrane Effective Practice and Organisation of Care Group.

We performed qualitative analysis of the evidence.

We included ten papers reporting results from six intervention studies. Overall, design quality and analysis limited the risks of bias. Several CCT programmes provided strong evidence of a positive impact on the use of health services, nutritional status and health outcomes, respectively assessed by anthropometric measurements  and self‐reported episodes of illness. It is hard to attribute these positive effects to the cash incentives specifically because other components may also contribute. Several studies provide evidence of positive impacts on the uptake of preventive services by children and pregnant women. We found no evidence about effects on health care expenditure.

Conditional cash transfer programmes have been the subject of some well‐designed evaluations, which strongly suggest that they could be an effective approach to improving access to preventive services. Their replicability under different conditions ‐ particularly in more deprived settings ‐ is still unclear because they depend on effective primary health care and mechanisms to disburse payments. Further rigorous evaluative research is needed, particularly where CCTs are being introduced in low income countries, for example in Sub‐Saharan Africa or South Asia.