This research deals with co-operation in the MST, its possibilities for rural workers' struggle for social transformation and its limits for human emancipation. What are the foundations of cooperation and capitalist society, the emergence of cooperativism, its creators and cooperative thinking, its role in the class struggle; cooperative experiences and ideals in Brazil, the contradictions of cooperativism, which arose with a contestatory character, based on the ideals of utopian socialists, to workers who organised themselves against the situation of extreme exploitation and pauperism in which they found themselves. And with a conservative reformist character, as it was framed by the capitalist system to serve the interests of capital reproduction and accumulation. I highlight the concept that the Landless Rural Workers' Movement (MST) defends and to what extent this concept of cooperativism differs from the traditional one; what role cooperation and cooperativism play in the struggle of rural workers against the onslaught of capital. Finally, the advances of co-operativism in the MST's struggle and the limits to human emancipation.