The last two decades witnessed an unprecedented decline in poverty across the developing world, a decline partly explained by the adoption of social cash transfer programs. Ironically, Latin America, traditionally the world’s most unequal region, has been a global trendsetter in this regard. Beginning in the late 1990s, governments across the region and across the ideological spectrum began adopting conditional cash transfer (CCT) programs, which award poor families regular stipends conditional on their children attending school and/or getting regular medical check-ups, and non-contributory pension (NCP) schemes for low-income and/or uncovered seniors. There is robust evidence that CCT programs achieve their short-term goals of reducing poverty while increasing school attendance and usage of health services. However, they do not improve learning and appear to be failing at their long-term goal of breaking the intergenerational transmission of poverty. Likely as a result of low-quality education, long-term CCT beneficiaries do not have significantly better economic prospects than comparable non-beneficiaries. CCTs also have electoral effects—there is robust evidence from across the region that they increase support for incumbent presidential candidates. CCTs were a response to the two big transformations the region underwent during the 1980s: the debt crisis and subsequent lost decade and the transition of most countries to democracy. Increased economic insecurity following the crisis and subsequent neoliberal reforms represented both a threat to the survival of newly elected governments and an opportunity for politicians to win over voters through increased social assistance. Pioneered by Mexico and Brazil in the mid-1990s, CCTs were by far the most effective policies to emerge from that context. They quickly diffused across the region, often with support from international financial institutions. Counterintuitively, adoption appears to be unrelated to the ascendance of left-wing governments in the region during the 2000s. The politics of CCT design are less understood. The myriad ways in which design can be conceptualized and measured, combined with the relative newness of this literature, have limited the accumulation of knowledge. It does appear that left-wing governments adopt more expansive CCTs and de-emphasize conditionality enforcement. Whereas their initial adoption and expansion, which coincided with the 2000s economic boom, proved politically easy, further reductions in poverty will require politically difficult choices, namely, raising taxes and/or redirecting funds away from programs benefiting the better-off. Improving the long-term effectiveness of CCTs will require improving education quality, which in turn will require challenging the region’s powerful teachers’ unions.