National large-scale assessments (NLSA) have spread rapidly since the 1990s, but contrary to arguments of diffusion theories, not every country with large-scale assessments develop test-based accountability (TBA). The diverse-case comparison presented in this article demonstrates that the interaction between global pressures and domestic policy legacies produces a variety of uses of standardized tests. Foreign training of experts and a strong assessment tradition made TBA flourish in Chile when supporters could avoid the consequences of accountability and opposition was weak. Despite similar assessment traditions, Colombia developed soft accountability because of the lack of incentives to redistribute education responsibilities, and strong teacher opposition. Argentina rejected accountability because testing had limited legitimacy, governments avoided responsibility for results, and teachers opposed TBA. Findings suggest two lessons: testing expansion does not indicate convergence toward TBA, and we need further exploration of the feasibility and effects of alternative uses of NLSA to promote quality.