Abstract: The objective of this chapter is the critical analysis of the primary tool for collective rights defense in Brazil: the class action lawsuit that is part of the Brazil’s microsystem for collective litigation. The key question is whether the country’s class action system has satisfactorily served its purpose of deterring and punishing rights violations by large businesses in Brazil. Our hypothesis is that such tool has proved insufficient as a remedy for infringements of the rights of third parties (consumers, workers, investors and even government organs) by private companies.