While access to social security is first a matter of rights, it is also useful to review its effects on outcomes commonly found in development and anti-poverty agenda in developing countries. This review can help to better assess the relevance to invest public resources in social protection in a context where these resources are quite limited and the needs are many. This is the purpose of this Compendium. The focus has been placed on non-contributory programmes in developing countries. In the last 15 years, large-scale non-contributory social transfer programmes have become a core component of poverty reduction strategies in many developing countries. The objectives, design and institutionalisation of these programmes differ, depending on their financial, administrative and research capacity. Overall, these programmes make a significant contribution to addressing poverty and vulnerability amongst the poor and poorest households in developing countries. This compendium aims to provide a concise review of the known effects of non-contributory social transfer programmes in developing countries on poverty and vulnerability. A searchable compendium matrix provides detailed information on the effects of social transfers, including a full list of country programmes. The compendium focuses on the main findings of available studies on the outcomes of social transfer programmes for key dimensions of wellbeing.