Brazil and South Africa went through a process of political transition, in the end of which the enactment of their Constitutions was a milestone in the formalization and universalization of their social policies. By comparison, these two countries have similar socio-economic and policies trajectories in the democratic period. After a period of promotion of economic restructure and stabilization reforms, social issues were strengthened, becoming the main item in the conduct of public policies. Therefore, in the present moment the two countries face the social challenges of poverty reduction, crystallizing the institutionalization of social assistance, and providing the construction of a social protection state. The spread of social welfare policies is a new paradigm for the promotion of public policies in the twenty-first century.