Federalism is a political set of principles of action and institution whose purpose is to accommodate unity with diversity without destroying one or the other, and it is not a surprise if social scientists can find in federations – as in Empires - a lot of empirical evidence on monetary plurality and complementarity. This paper addresses the issue of monetary federalism, considering that it is a figure of complementarity among monies caused by locality. The proposed analysis is based on the hypothesis of institutional complementarity which assumes that the principles of organization of a monetary system have to fit, in a way or another, with those of the political organization of the society within which the monetary system functions as a community of account (of debts) and a set of means of payments (of these debts). The first section starts by a developpement of the theoretical idea that with such a definition, money has intrinsically a federal structure combining unicity (of the unit of account) and plurality-diversity (of the means of payment). Then it comes to the fact that this intrinsic federal structure of modern money does not appear clearly in the monetary institutions of most of the existing federations, including Argentina where monetary plurality has always been outstanding. We explain this paradox in term of political repression of monetary federalism. The following sections are devoted to an examination of the practical monetary federalism existing in Argentina from 1984 to 2003. A second section tackles the question of why Argentina exhibits a noteworthy case of monetary federalism, even if it is a repressed one, and describes the different waves of issuances of provincial fiscal monies since the foundation of the federal Republic. A third section focuses on the complementary fiscal money issued by the Province of Tucuman between 1985 and 2003 ; it examines why it was issued, and how it functionned at its outset and evolved. Section 4 at last examines if the bocade was an efficient device, given the political and economic environment in which its life developped until its terminal redeeming by the federal State.