The International Labour Organization estimates that there are 12.5 million children and adolescents under the age of fifteen currently working in Latin America and the Caribbean. Of these, 9.6 million (77%) perform tasks that pose a risk to their physical and psychological health. This article presents a brief comparative analysis of child labor in Brazil and Uruguay in order to discuss the challenges of confronting this phenomenon in two very different countries that have embraced divergent strategies to deal with similar problems. To do this, the article presents an overview of the incidence of child labor in Brazil and Uruguay and seeks to demonstrate how far the category of labor is from a universal definition in the academic world, which is also repeated in the debate on the definition of child labor. It is possible to identify different moments of the debate in Latin America regarding the concept of child labor. Some approaches have been more contextualized than others, but all remain controversial and are sometimes considered incomplete. It will also consider the changes in the world of labor and how they interfere in this phenomenon. Despite advances in the fight against child labor overall, Brazil is starting to stagnate in its efforts to reduce the number of child and adolescent workers, and its challenge is to find new political solutions to address this problem. Uruguay still needs to place the issue more centrally on the nation’s political and social agenda in order to guarantee consistent research on the problem that can guide its policy responses.