In the mid-1990s, Brazil and Mexico created innovative social policies known as Conditional Cash Transfers (CCTs). Since then, CCTs have spread to countries throughout Latin America and beyond. While these programs reflect a new development norm, their spread is surprising given that some emulating countries lack the basic education and health infrastructure to support increased demand from beneficiaries. This article draws on a policy diffusion framework to explain the spread of CCTs. The author contrasts domestic preconditions (political ideology, state capacity and human development levels) with international pressure (neighborhood effects, professional norm-creation and financial inducements by international financial institutions) to explain the diffusion of CCTs. In order to elucidate the mechanisms that drive diffusion processes, the article draws on mixed methods to uncover learning and emulation among actors.