OBJECTIVE: To provide an overview of Conditional Cash Transfer (CCT) programmes in low and middle income countries and present the evidence to date on their contribution to improvements in health and the encouragement of healthy behaviours. METHODS: Several bibliographic databases and websites were used to identify relevant studies. To be included, a study had to provide evidence of effects of a financial incentive conditional upon specific health-related behaviours. Only experimental or quasi-experimental study designs were accepted. RESULTS: We identified 13 CCT programmes, whose effects had been evaluated, mostly in Latin-American countries. Their results suggest that CCTs have been effective in increasing the use of preventive services, improving immunisation coverage, certain health outcomes and in encouraging healthy behaviours. CONCLUSION: CCTs can be valuable tools to address some of the obstacles faced by populations in poorer countries to access health care services, or maybe to modify risky sexual behaviours. However, CCTs need to be combined with supply-side interventions to maximise effects. Finally, some questions remain regarding their sustainability and cost-effectiveness.