The research on federal systems in many countries has proven to have permanent relevance, specially recently, in face of the dynamics related to the nature of nation-states in Europe as well as in Latin America. Within this context, this work discusses cooperative mechanisms in the framework of the political dynamics in Germany and Brazil from the nineties onwards. The purpose is to compare constitutional principles guiding both federative models, the fiscal federalism adopted in both countries and the composition and role of the upper chamber in both cases. Recent tendencies, tensions and political negotiations set the scope and the limits of the predominating cooperative federalism in Germany and Brazil and shall be analyzed through case studies that present the main federative conflicts. The main results point to the need of cooperative mechanisms for the fulfillment of the federative project in both countries, even though major issues about the fiscal federalism persist since the beginning of the nineties, especially in Germany. This tends to stimulate conflicts between the federal government and the states, and among subnational units, demanding a permanent willingness for political negotiations.