A concrete alternative economy has been developing in Brazil since the end of the 1980s, which involves both country and city workers and is based on the structuring of solidary economic enterprises (SEE), in which selfdeveloped popular cooperatives stand out. This alternative economy has brought with it new challenges, among them the need for ongoing technical, administrative and political education as a fundamental element in the search for equilibrium between social and economic issues. This article analyzes the Solidary Economy in Brazil, particularly from the standpoint of the challenges faced by the cooperative agrarian reform of the Landless Rural Workers' Movement (MST). Starting from the historical process in which landless workers began to organize, agrarian cooperation has become an important tool for the workers' settlements. On the other hand, the reality of the capitalist economy has obliged cooperative workers to adopt administrative tools that contribute toward the social and economic viability of their enterprises. The backdrop to this issue is the need to deepen the debate about the possibility of conceiving SEEs that are capable of survival and growth in the capitalist economy, incorporating technical progress, rationalizing productive and work organization, bringing social benefits to their members, and acting as the political force behind the workers' struggles, as well as ensuring democratic and autonomous administration.