Poverty is a multidimensional phenomenon closely related with the low accumulation of human capital and scant economic opportunities for the poor. Government efforts to help households to overcome poverty require actions on multiple fronts. Although sustainable economic growth, macroeconomic stability and governance are essential ingredients for poverty reduction, they are not sufficient. Specific actions to boost capacity (assets), opportunities and risk management options for the poorest and most excluded groups are also required to promote greater equity and increase the impact of growth on poverty. The governments of the region, with the support of multilateral institutions such as the IDB, are making important efforts to scale up innovative programs to increase the capabilities and economic opportunities of the poor to ensure attaining the Millennium Development Goals.\n\nIncreasingly the implementation of these programs in Latin America and the Caribbean has been accompanied by significant efforts and resources to evaluate their impact and effectiveness. The implementation and evaluation of the portfolio of interventions to improve the capabilities and opportunities of the poor has produced useful lessons that have helped identify best practices to reduce poverty and inequality and promote MDG attainment. This document reviews these experiences placing emphasis on extracting lessons from projects and programs for which impact evaluations are available in order to rigorously assess the development effectiveness of these interventions. All evaluations included in the review have a control group and use the rigorous statistical methodologies (randomization or experimental design, propensity score matching, and instrumental variables) estimate the impact of the interventions. Using this criteria 51 studies from 47 social programs were included.\n\nThe paper analyzes the topics that usually arise from systematic reviews of development programs (specifically, poverty reduction programs) and initiates a discussion about them. These topics include (i) identifying general relationships and treatment effects through the synthesis of individual study results; (ii) finding reasons for conflicting evidence; (iii) answering questions, using variations in studies, that could not have been answered in the individual component studies; (iv) explaining variations in practice; (v) reviewing the evidence on the subjective experience of an intervention, and/or (vi) building connections between related areas of research.\n\nWhile impact evaluations of similar projects in different countries (or regions) are not generally expected to yield the same results, the mounting evidence increasingly allows us to infer some important lessons to design and improve social programs in the region. The results presented in this review show a mostly positive picture of the average impact of the programs evaluated. Results of the evaluations have also proven to be useful, not only for measuring impacts, but also for identifying program weaknesses (e.g. problems with targeting mechanisms or groups that are not reaping the full benefits of the program) and induce the adjustments necessary to increase program effectiveness. The evaluation results and the experience in implementing these programs also raise various issues for the reform of social and fiscal policies in order to make public social expenditure more effective, pro-poor, and fiscally sustainable. These issues include, among others, the need to design social programs as harmonious components of extreme poverty eradication policies and social protection systems, taking advantage of instrument complementary; take advantage of cash transfers and the need to include conditionality in program design; include strong components for beneficiary training and monitoring of beneficiary responses in some interventions; ensure an institutional environment that is conducive to program sustainability; go beyond increased access to improve the quality of services provided; respond to political and fiscal questioning of interventions with demonstrated cost effectiveness; and ensure cost-effective targeting.