Economists hold that cooperatives should be free to carry on business for profit in the market. And, as Marxists have traditionally been inimical to markets, it is hardly surprising that they have taken little interest in a cooperative system so far. Moreover, borrowing a saying by Marx, they argue that workers joining cooperatives become «their own capitalists» and that the establishment of a system of producer cooperatives would far from further the abolition of capitalism appreciably. Lastly, they claim that cooperative firms have proved unfit to supplant their capitalistic rivals or bring about a new production mode. This paper discusses Marxist criticisms of cooperatives in an attempt to refute the assumptions behind them. In the author's view, a system of Vanek-type LMF cooperatives would capsize the capital-labour relation which is the pivot of capitalistic systems and would consequently amount to a revolution in full keeping with Marxian theory.