The democratic question became of an ardent actuality within cooperative banks since the end of the 1990's. Founding element of human-sized organizations that were the first mutual or cooperative Caisses, is democracy running the risk to dissolve by necessity in the mature and hybrid giants that are the big banking cooperative groups nowadays? The present article unveils a multidisciplinary synthesis made possible by the conjunction of three researchers studying cooperative banks through three complementary angles: law, economy and management. After a first inventory of the possible symptoms of the disappearance of democracy inherent to the cooperative project, a more differentiating diagnosis is proposed, followed by an outline of some working leads for a creative evolution of cooperative democracy.